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【327685】2022年湖北省黄冈市孝感市咸宁市中考数学真题

时间:2025-01-20 19:59:45 作者: 字数:21651字
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2022年湖北省黄冈市、孝感市、咸宁市中考数学真题

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注意事项:

1.答题前填写好自己的姓名、班级、考号等信息

2.请将答案正确填写在答题卡上



评卷人

得分




一、选择题

1.﹣5的绝对值是( )
A
5
B
.﹣5
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

2.某几何体的三视图如图所示,则该几何体是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
A
.圆锥
B
.三棱锥
C
.三棱柱
D
.四棱柱

3.北京冬奥会开幕式的冰雪五环由我国航天科技建造,该五环由21000LED灯珠组成,夜色中就像闪闪发光的星星,把北京妆扮成了奥运之城,将数据21000用科学记数法表示为(       
A
21×103
B2.1×104
C2.1×105
D0.21×106

4.下列图形中,对称轴最多的是(       
A
.等边三角形
B
.矩形
C
.正方形
D
.圆

5.下列计算正确的是(       
A
a2a4a8
B.(-2a23=-6a6
Ca4÷aa3
D2a3a5a2

6.下列调查中,适宜采用全面调查方式的是(       
A
.检测“神舟十四号”载人飞船零件的质量
B
.检测一批LED灯的使用寿命
C
.检测黄冈、孝感、咸宁三市的空气质量
D
.检测一批家用汽车的抗撞击能力

7.如图,在RtABC中,∠C90°,∠B30°AB8,以点C为圆心,CA的长为半径画弧,交AB于点D,则弧AD的长为(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
D
2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

8.如图,在矩形ABCD中,ABBC,连接AC,分别以点AC为圆心,大于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> AC的长为半径画弧,两弧交于点MN,直线MN分别交ADBC于点EF.下列结论:
四边形AECF是菱形;
②∠
AFB2∠ACB
ACEFCFCD
AF平分∠BAC,则CF2BF
其中正确结论的个数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
A
4
B
3
C
2
D
1

评卷人

得分




二、填空题

9.若分式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 有意义,则x的取值范围是________

10.如图,直线ab,直线c与直线ab相交,若∠154°,则∠3________度.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

11.已知一元二次方程x2﹣4x+30的两根为x1x2,则x1x2_____

12.如图,点BECF在一条直线上,ABDE,且AB=DE,请添加一个条件_____,使△ABC≌△DEF
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

13.小聪和小明两个同学玩“石头,剪刀、布“的游戏,随机出手一次是平局的概率是________

14.如图,有甲乙两座建筑物,从甲建筑物 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点处测得乙建筑物 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点的俯角 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点的俯角 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 为两座建筑物的水平距离.已知乙建筑物的高度 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则甲建筑物的高度 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ________ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> .( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,结果保留整数).
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

15.勾股定理最早出现在商高的《周髀算经》:“勾广三,股修四,经隅五”.观察下列勾股数:3455121372425;…,这类勾股数的特点是:勾为奇数,弦与股相差为1,柏拉图研究了勾为偶数,弦与股相差为2的一类勾股数,如:681081517;…,若此类勾股数的勾为2mm≥3m为正整数),则其弦是________(结果用含m的式子表示).

16.如图1,在△ABC中,∠B36°,动点P从点A出发,沿折线ABC匀速运动至点C停止.若点P的运动速度为1cm/s,设点P的运动时间为ts),AP的长度为ycm),yt的函数图象如图2所示.当AP恰好平分∠BAC时,t的值为________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

评卷人

得分




三、解答题

17.先化简,再求值:4xy2xy-(-3xy),其中x2y=-1

18.某班去革命老区研学旅行,研学基地有甲乙两种快餐可供选择,买1份甲种快餐和2份乙种快餐共需70元,买2份甲种快餐和3份乙种快餐共需120元.
(1)
买一份甲种快餐和一份乙种快餐各需多少元?
(2)
已知该班共买55份甲乙两种快餐,所花快餐费不超过1280元,问至少买乙种快餐多少份?

19.为落实“双减”政策,优化作业管理,某中学从全体学生中随机抽取部分学生,调查他们每天完成书面作业的时间t(单位:分钟).按照完成时间分成五组:A组“t≤45”B组“45t≤60”C组“60t≤75”D组“75t≤90”E组“t90”.将收集的数据整理后,绘制成如下两幅不完整的统计图. 根据以上信息,解答下列问题:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(1)
这次调查的样本容量是 ,请补全条形统计图;
(2)
在扇形统计图中,B组的圆心角是 度,本次调查数据的中位数落在 组内;
(3)
若该校有1800名学生,请你估计该校每天完成书面作业不超过90分钟的学生人数.

20.如图,已知一次函数y1kxb的图像与函数y2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> x0)的图像交于A6,- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ),B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> n)两点,与y轴交于点C,将直线AB沿y轴向上平移t个单位长度得到直线DEDEy轴交于点F
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(1)
y1y2的解析式;
(2)
观察图像,直接写出y1y2x的取值范围;
(3)
连接ADCD,若△ACD的面积为6,则t的值为

21.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的外接圆, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的直径, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 与过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的切线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 平行, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 相交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(1)
求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的长.

22.为增强民众生活幸福感,市政府大力推进老旧小区改造工程.和谐小区新建一小型活动广场,计划在360m2的绿化带上种植甲乙两种花卉.市场调查发现:甲种花卉种植费用y(元/m2)与种植面积xm2)之间的函数关系如图所示,乙种花卉种植费用为15/m2
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(1)
x≤100时,求yx的函数关系式,并写出x的取值范围;
(2)
当甲种花卉种植面积不少于30m2,且乙种花卉种植面积不低于甲种花卉种植面积的3倍时.
如何分配甲乙两种花卉的种植面积才能使种植的总费用w(元)最少?最少是多少元?
受投入资金的限制,种植总费用不超过6000元,请直接写出甲种花卉种植面积x的取值范围.

23.问题背景:
一次数学综合实践活动课上,小慧发现并证明了关于三角形角平分线的一个结论.如图1,已知AD是△ABC的角平分线,可证 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> .小慧的证明思路是:如图2,过点CCEAB,交AD的延长线于点E,构造相似三角形来证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(1)
尝试证明:请参照小慧提供的思路,利用图2证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
应用拓展:如图3,在RtABC中,∠BAC90°D是边BC上一点.连接AD,将△ACD沿AD所在直线折叠,点C恰好落在边AB上的E点处.
AC1AB2,求DE的长;
BCm,∠AED <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,求DE的长(用含m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的式子表示).

24.抛物线yx24x与直线yx交于原点O和点B,与x轴交于另一点A,顶点为D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(1)
直接写出点B和点D的坐标;
(2)
如图1,连接ODPx轴上的动点,当tan∠PDO <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时,求点P的坐标;
(3)
如图2M是点B关于抛物线对称轴的对称点,Q是抛物线上的动点,它的横坐标为m0m5),连接MQBQMQ与直线OB交于点E.设△BEQ和△BEM的面积分别为S1S2,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的最大值.

参考答案

1.A

【解析】
根据负数的绝对值等于它的相反数可得答案.
解:|﹣5|=5
故选A

2.C

【解析】
由主视图和左视图得出该几何体是柱体,再结合俯视图可得答案.
解:由三视图知,该几何体是三棱柱,
故选:C

3.B

【解析】
首先思考科学记数法表示数的形式,再确定an的值,即可得出答案.
21000=2.1×10
4
故选:B

4.D

【解析】
试题因为等边三角形有三条对称轴;矩形有两条对称轴;正方形有四条对称轴;圆有无数条对称轴.一般地,正多边形的对称轴的条数等于边数.故选D.

5.C

【解析】
根据同底数幂的乘法、积的乘方、同底数幂的除法、合并同类项逐个选项判断即可.
A
a2a4a6,故A错误;
B
、(-2a23=-8a6,故B错误;
C
a4÷aa3,故C正确;
D
2a3a5a,故D错误,
故选:C

6.A

【解析】
根据全面调查与抽样调查的特点,逐一判断即可解答.
解:A、检测“神舟十四号”载人飞船零件的质量,适宜采用全面调查的方式,故A符合题意;
B
、检测一批LED灯的使用寿命,适宜采用抽样调查的方式,故B不符合题意;
C
、检测黄冈、孝感、咸宁三市的空气质量,适宜采用抽样调查的方式,故C不符合题意;
D
、检测一批家用汽车的抗撞击能力,适宜采用抽样调查的方式,故D不符合题意.
故选:A

7.B

【解析】
连接CD,根据∠ACB=90°,∠B=30°可以得到∠A的度数,再根据AC=CD以及∠A的度数即可得到∠ACD的度数,最后根据弧长公式求解即可.
解:连接CD,如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
ACB=90°,∠B=30°AB=8
∴∠
A=90°-30°=60°AC= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> AB=4
由题意得:AC=CD
∴△
ACD为等边三角形,
∴∠
ACD=60°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的长为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
故选:B

8.B

【解析】
根据作图可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,且平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的交点为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,证明四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 为菱形,即可判断①,进而根据等边对等角即可判断②,根据菱形的性质求面积即可求解.判断③,根据角平分线的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,根据含30度角的直角三角形的性质,即可求解.
如图,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的交点为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
根据作图可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,且平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 是平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 垂直平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 是菱形,故①正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> AFB2∠ACB;故②正确;
由菱形的面积可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ACEFCFCD;故③不正确,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
AF平分∠BAC <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> CF2BF.故④正确;
故选B

9. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
根据分式有意义的条件即可求解.
解:∵分式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 有意义,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

10.54

【解析】
根据对顶角相等和平行线的性质“两直线平行同位角相等”,通过等量代换求解.
因为a∥b
所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
因为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 是对顶角,
所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
因为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
故答案为:54

11.3

【解析】
直接根据一元二次方程ax2+bx+c0a≠0)的根与系数的关系求解即可.
解:∵一元二次方程x2﹣4x+30的两根为x1x2
x1x2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 3
故答案为3

12.A=∠DBC=EFBE=CF或∠ACB=∠F

【解析】
判定一般三角形全等一共有四种方法,根据这四种方法一一选择即可.
解:添加BE=CF
BE=CF
BC=EF
ABDE
∴∠
B=∠DEF
AB=DE
∴△
ABC≌△DEFSAS).
故答案为:AB=DE(答案不唯一).

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
列表表示所有可能出现的结果,再确定符合条件的结果,根据概率公式计算即可.
解:列表如下:


石头

剪子

石头

(石头,石头)

(石头,剪子)

(石头,布)

剪子

(剪子,石头)

(剪子,剪子)

(剪子,布)

(布,石头)

(布,剪子)

(布,布)


一共有9种可能出现的结果,每种结果出现的可能性相同,出手相同的时候即为平局,有3种,所以随机出手一次平局的概率是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

14. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,进而可得出答案.
解:如图,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
根据题意可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 是矩形,
从甲建筑物 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点处测得乙建筑物 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点的俯角 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 点的俯角 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 为两座建筑物的水平距离,乙建筑物的高度 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
经检验 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 是原分式方程的解且符合题意,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

15.m2+1

【解析】
2
m为偶数,设其股是a,则弦为a+2,根据勾股定理列方程即可得到结论.
∵2
m为偶数,
设其股是a,则弦为a+2
根据勾股定理得,(2m2+a2=a+22
解得a=m2-1
弦长为m2+1
故答案为:m2+1

16. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ## <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
根据函数图像可得AB=4=BC,作∠BAC的平分线AD,∠B36°可得∠B=∠DAC36°,进而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,由相似求出BD的长即可.
根据函数图像可得AB=4AB+BC=8
BC=AB=4
∵∠
B36°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
作∠BAC的平分线AD
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
∴∠
BAD=∠DAC36°=∠B
AD=BD <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
AD=BD=CD
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
∵∠
DAC=∠B36°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得:  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> (舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> (s)
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> .

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
根据整式的加减运算化简,然后将字母的值代入即可求解.
解:原式=4xy2xy+3xy
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
5xy
x2y=-1时,
原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

18.(1)买一份甲种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 元,一份乙种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
至少买乙种快餐37

【解析】
1)设一份甲种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 元,一份乙种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 元,根据题意列出方程组,解方程即可求解;
2)设购买乙种快餐 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 份,则购买甲种快餐 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 份,根据题意列出一元一次不等式,解不等式即可求解.
(1)
解:设一份甲种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 元,一份乙种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 元,根据题意得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
答:买一份甲种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 元,一份乙种快餐需 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 元;
(2)
设购买乙种快餐 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 份,则购买甲种快餐 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 份,根据题意得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 至少买乙种快餐37
答:至少买乙种快餐37份.

19.(1)100,图形见解析
(2)72
C
(3)
估计该校每天完成书面作业不超过90分钟的学生有1710人.

【解析】
1)根据C组的人数和所占的百分比,可以计算出本次调查的人数,然后即可计算出D组的人数,从而可以将条形统计图补充完整;
2)根据统计图中的数据,可以计算出B组的圆心角的度数,以及中位数落在哪一组;
3)根据题意和统计图中的数据,可以计算出该校每天完成书面作业不超过90分钟的学生人数.
(1)
这次调查的样本容量是:25÷25%=100
D组的人数为:100-10-20-25-5=40
补全的条形统计图如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
故答案为:100
(2)
在扇形统计图中,B组的圆心角是:360°× <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> =72°
本次调查了100个数据,第50个数据和51个数据都在C组,
中位数落在C组,
故答案为:72C
(3)
1800×
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> =1710(人),
答:估计该校每天完成书面作业不超过90分钟的学生有1710人.

20.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(3)2


【解析】
1)将两函数AB的坐标值分别代入两个函数解析式求出未知系数即可;
2)由图像可知当xAB两点之间时y1y2,,所以x取值在AB两点横坐标之间;
3)根据平移性质可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> CF=t,求出两直线之间的距离即为△ACD的高CG,通过AC坐标求出线段AC长,列出△ACD面积= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的代数式求解即可.
(1)
一次函数y1kxb的图像与函数y2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> x0)的图像交于A6,- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ),B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> n)两点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>         <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>     <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
y1y2的解析式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
从图像上可以看出,当xAB两点之间时,y1y2
x的取值范围为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
CGDEG,如图,
直线DE是直线AB沿y轴向上平移t个单位长度得到,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> CF=t
直线AB的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
直线ABy轴的交点为C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,与x轴的交点为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
即直线ABxy坐标轴的交点到原点O的距离相等,
∴∠
FCA=45°
CGDE  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
CGACCG等于平行线ABDE之间的距离,
∴∠
GCF=∠GFC=45°
CG= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> = <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
AC两点坐标为:A6,- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ),C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
线段AC= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
∵△
ACD的面积为6
∴3
t=6
解得:t=2

21.(1)证明见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
1)由切线的性质和 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,由垂径定理可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,从而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 垂直平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,最后利用垂直平分线的性质即可得证;
2)先利用勾股定理得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,然后利用两组对应角相等证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,从而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,代入数据计算即可.
(1)
证明:∵直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 垂直平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
如图,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
由(1)知: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 的长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

22.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)①
甲种花卉种植90m2, 乙种花卉种植270m2时,种植的总费用w最少,最少为5625元;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
1)根据函数图像分两种情况, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> y为常数, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> y为一次函数,设出函数解析式,将两端点值代入求出解析式,将两种情况汇总即可;
2)①设甲种花卉种植面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则乙种花卉种植面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,根据乙的面积不低于甲的3倍可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,利用总费用等于两种花卉费用之和,将m分不同范围进行讨论列出总费用代数式,根据m的范围解出最小值进行比较即可;
x按图像分3种范围分别计算总费用的取值范围即可.
(1)
由图像可知,当甲种花卉种植面积 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> m2时,费用y保持不变,为30(元/m2),
所以此区间的函数关系式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
当甲种花卉种植面积 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> m2时,函数图像为直线,
设函数关系式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
x=40时,y=30,当x=100时,y=15,代入函数关系式得:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时,yx的函数关系式应为:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
设甲种花卉种植面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则乙种花卉种植面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
乙种花卉种植面积不低于甲种花卉种植面积的3倍,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
m的范围为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
此时当m最小时,w最小,
即当m=30时,w有最小值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> (元),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
此时当m=90时,离对称轴m=50最远,w最小,
即当m=90时,w有最小值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> (元)
∵5625
5850
m=90时种植的总费用w最少,为5625元,此时乙种花卉种植面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> =270
故甲种花卉种植90m2, 乙种花卉种植270m2时,种植的总费用w最少,最少为5625元.
由以上解析可知:
1)当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时,总费用= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> (元),
2)当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时,总费用= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
3)当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时,总费用= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> (元),
综上,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时种植总费用不会超过6000元,
所以甲种花卉种植面积x的取值范围为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

23.(1)详见解析
(2)①
DE= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ;② <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
1)利用ABCE,可证得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,由AD平分∠BAC,可知AC=EC,即可证得结果;
2)利用(1)中的结论进行求解表示即可.
(1)
解:∵ABCE
∴∠
BAD=∠DEC
AD平分∠BAC
∴∠
BAD=∠CAD
∴∠
CAD=∠DEC
AC=EC
∵∠
BDA=∠CDE
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(2)
由折叠可知,AD平分∠BACCD=DE
由(1)得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
AC1AB2
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
解得:CD= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
DE= CD= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
由折叠可知∠AED=∠C= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
由①可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
即: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

24.(1)B5,5),D2,-4);
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>

【解析】
1)将两函数解析式联立可求得B点坐标,将一般式转换为顶点式可求出D点坐标;
2)如图所示,过DDEx轴与点E,则E2,0),则tanEDO= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,当PE上时,则满足tanPDO <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,如图所示,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时,过D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 于点G,由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,可得OG=OE=2DG=DE=4,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,解出可得n的值进而可求出P的坐标;
3)由题易得:M-1,5), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,直线MQ的解析式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,令 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,由BM=6,可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,求出此二次函数的最值即可.
(1)
解:将yx24xyx联立得:xx24x
解得:x=5x=0(舍去),
x=5代入yxy=5
B点坐标为(5,5),
将函数yx24x转换为顶点式得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,故顶点D为(2,-4),
B5,5),D为(2,-4);
(2)
如图所示,过DDEx轴与点E
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
E2,0),则tan∠EDO= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,当PE上时,则满足tan∠PDO <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
如图所示,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时,过O <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 于点G
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
OG=OE=2DG=DE=4
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> n=0(舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
综上所述 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
(3)
解:由题易得:M-1,5), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
则直线MQ的解析式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
BM=6
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> ,函数开口向下,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a> 取最大值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/276/" title="黄冈" class="c1" target="_blank">黄冈</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1032/" title="咸宁" class="c1" target="_blank">咸宁</a> <a href="/tags/1104/" title="孝感" class="c1" target="_blank">孝感</a>