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【327683】2022年湖北省鄂州市中考数学真题

时间:2025-01-20 19:59:37 作者: 字数:24444字
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绝密·启用前

2022年湖北省鄂州市中考数学真题

题号

总分

得分





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.实数9的相反数等于(  )
A
.﹣9
B
+9
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
.﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

2.下列计算正确的是(  )
A
b+b2b3
Bb6÷b3b2
C.(2b36b3
D3b﹣2bb

3.孙权于公元2214月自公安“都鄂”,在西山东麓营建吴王城,并取“以武而昌”之意,改鄂县为武昌,下面四个汉字中,可以看作是轴对称图形的是(  )
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

4.如图所示的几何体是由5个完全相同的小正方体组成,它的主视图是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

5.如图,直线l1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> l2,点CA分别在l1l2上,以点C为圆心,CA长为半径画弧,交l1于点B,连接AB.若∠BCA150°,则∠1的度数为(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A
10°
B
15°
C
20°
D
30°

6.生物学中,描述、解释和预测种群数量的变化,常常需要建立数学模型.在营养和生存空间没有限制的情况下,某种细胞可通过分裂来繁殖后代,我们就用数学模型2n来表示.即:21222423824162532,……,请你推算22022的个位数字是(       
A
8
B
6
C
4
D
2

7.数形结合是解决数学问题常用的思想方法.如图,一次函数ykx+bkb为常数,且k0)的图象与直线y <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x都经过点A31),当kx+b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x时,x的取值范围是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A
x3
B
x3
C
x1
D
x1

8.工人师傅为检测该厂生产的一种铁球的大小是否符合要求,设计了一个如图(1)所示的工件槽,其两个底角均为90°,将形状规则的铁球放入槽内时,若同时具有图(1)所示的ABE三个接触点,该球的大小就符合要求.图(2)是过球心及ABE三点的截面示意图,已知⊙O的直径就是铁球的直径,AB是⊙O的弦,CD切⊙O于点EACCDBDCD,若CD=16cmAC=BD=4cm,则这种铁球的直径为(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A
10cm
B
15cm
C
20cm
D
24cm

9.如图,已知二次函数yax2+bx+cabc为常数,且a≠0)的图像顶点为P1m),经过点A21);有以下结论:①a0;②abc0;③4a+2b+c1;④x1时,yx的增大而减小;⑤对于任意实数t,总有at2+bta+b,其中正确的有(  )   
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A
2
B
3
C
4
D
5

10.如图,定直线MN <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> PQ,点BC分别为MNPQ上的动点,且BC=12BC在两直线间运动过程中始终有∠BCQ=60°.点AMN上方一定点,点DPQ下方一定点,且AE <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> BC <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> DFAE=4DF=8AD=24 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,当线段BC在平移过程中,AB+CD的最小值为(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A
24 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
24 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
12 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
12 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

评卷人

得分




二、填空题

11.化简: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> = .

12.为了落实“双减”,增强学生体质,阳光学校篮球兴趣小组开展投篮比赛活动.6名选手投中篮圈的个数分别为233435,则这组数据的众数是_____

13.若实数ab分别满足a2﹣4a+30b2﹣4b+30,且ab,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值为 _____

14.中国象棋文化历史久远.某校开展了以“纵横之间有智慧   攻防转换有乐趣”为主题的中国象棋文化节,如图所示是某次对弈的残局图,如果建立平面直角坐标系,使“帥”位于点(﹣1,﹣2),“馬”位于点(2,﹣2),那么“兵”在同一坐标系下的坐标是_____
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

15.如图,已知直线y2x与双曲线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> k为大于零的常数,且x0)交于点A,若OA= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则k的值为 _____
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

16.如图,在边长为6的等边△ABC中,DE分别为边BCAC上的点,ADBE相交于点P,若BD=CE=2,则△ABP的周长为 _____
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

评卷人

得分




三、解答题

17.先化简,再求值: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,其中a3

18..为庆祝中国共产主义青年团成立100周年,某校举行了“青年大学习,强国有我”知识竞赛活动.李老师赛后随机抽取了部分学生的成绩(单位:分,均为整数),按成绩划分为ABCD四个等级,并制作了如下统计图表(部分信息未给出):

等级

成绩x/

人数

A

90≤x≤100

15

B

80≤x90

a

C

70≤x80

18

D

x70

7


 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(1)
表中a   C等级对应的圆心角度数为    
(2)
若全校共有600名学生参加了此次竞赛,成绩A等级的为优秀,则估计该校成绩为A等级的学生共有多少人?
(3)
A等级15名学生中有3人满分,设这3名学生分别为T1T2T3,从其中随机抽取2人参加市级决赛,请用列表或树状图的方法求出恰好抽到T1T2的概率.

19.如图,在矩形ABCD中,对角线ACBD相交于点O,且∠CDF=∠BDC、∠DCF=∠ACD
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(1)
求证:DF=CF
(2)
若∠CDF=60°DF=6,求矩形ABCD的面积.

20.亚洲第一、中国唯一的航空货运枢纽一一鄂州花湖机场,于2022319日完成首次全货运试飞,很多市民共同见证了这一历史时刻.如图,市民甲在C处看见飞机A的仰角为45°,同时另一市民乙在斜坡CF上的D处看见飞机A的仰角为30°,若斜坡CF的坡比=13,铅垂高度DG=30米(点EGCB在同一水平线上).求:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(1)
两位市民甲、乙之间的距离CD
(2)
此时飞机的高度AB,(结果保留根号)

21.在“看图说故事”活动中,某学习小组设计了一个问题情境:小明从家跑步去体育场,在那里锻炼了一阵后又走到文具店买圆规,然后散步走回家.小明离家的距离ykm)与他所用的时间xmin)的关系如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(1)
小明家离体育场的距离为 km,小明跑步的平均速度为 km/min
(2)
15≤x≤45时,请直接写出y关于x的函数表达式;
(3)
当小明离家2km时,求他离开家所用的时间.

22.如图,△ABC内接于⊙OP是⊙O的直径AB延长线上一点,∠PCB=∠OAC,过点OBC的平行线交PC的延长线于点D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(1)
试判断PC与⊙O的位置关系,并说明理由;
(2)
PC4tanA <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,求△OCD的面积.

23.某数学兴趣小组运用《几何画板》软件探究yax2a0)型抛物线图象.发现:如图1所示,该类型图象上任意一点M到定点 F0 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> )的距离MF,始终等于它到定直线ly=﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上的距离MN(该结论不需要证明),他们称:定点F为图象的焦点,定直线l为图象的准线,y=﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 叫做抛物线的准线方程.其中原点OFH的中点,FH=2OF=  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,例如,抛物线y <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x2,其焦点坐标为F0 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ),准线方程为ly=﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .其中MF=MNFH=2OH=1   
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(1)(
基础训练)
请分别直接写出抛物线y2x2的焦点坐标和准线l的方程:      
(2)(
技能训练)
如图2所示,已知抛物线y <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x2上一点P到准线l的距离为6,求点P的坐标;
(3)(
能力提升)
如图3所示,已知过抛物线yax2a0)的焦点F的直线依次交抛物线及准线l于点ABC.若BC2BFAF4,求a的值;
(4)(
拓展升华)
古希腊数学家欧多克索斯在深入研究比例理论时,提出了分线段的“中末比”问题:点C将一条线段AB分为两段ACCB,使得其中较长一段AC是全线段AB与另一段CB的比例中项,即满足: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .后人把 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 这个数称为“黄金分割”把点C称为线段AB的黄金分割点.
如图4所示,抛物线y <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x2的焦点F01),准线ly轴交于点H0,﹣1),E为线段HF的黄金分割点,点My轴左侧的抛物线上一点.当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,请直接写出△HME的面积值.

24.如图1,在平面直角坐标系中,RtOAB的直角边OAy轴的正半轴上,且OA=6,斜边OB=10,点P为线段AB上一动点.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(1)
请直接写出点B的坐标;
(2)
若动点P满足∠POB=45°,求此时点P的坐标;
(3)
如图2,若点E为线段OB的中点,连接PE,以PE为折痕,在平面内将△APE折叠,点A的对应点为A',当PA'⊥OB时,求此时点P的坐标;
(4)
如图3,若F为线段AO上一点,且AF=2,连接FP,将线段FP绕点F顺时针方向旋转60°得线段FG,连接OG,当OG取最小值时,请直接写出OG的最小值和此时线段FP扫过的面积.

参考答案

1.A

【解析】
根据相反数的定义:如果两个数只有符号不同,我们称其中一个数为另一个数的相反数,进行求解即可.
解:实数9的相反数是-9
故选A

2.D

【解析】
根据积的乘方“把积的每一个因式分别乘方,再把所得的幂相乘”,合并同类项“把同类项的系数相减,所得的结果作为系数,字母和字母的指数不变”,同底数幂的除法“底数不变,指数相减”进行计算即可得.
解:A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,选项说法错误,不符合题意;
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,选项说法错误,不符合题意;
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,选项说法错误,不符合题意;
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,选项说法正确,符合题意;
故选D

3.D

【解析】
根据轴对称图形的概念,轴对称图形两部分沿对称轴折叠后可重合,进行解答即可得.
解:A、“以”不是轴对称图形,选项说法错误,不符合题意;
B
、“武”不是轴对称图形,选项说法错误,不符合题意;
C
、“而”不是轴对称图形,选项说法错误,不符合题意;
D
、“昌”是轴对称图形,选项说法正确,符合题意;
故选D

4.A

【解析】
根据从正面看到的图形是主视图,即可得.
解:从前面看,第一层是两个小正方形,第二层左边一个小正方形,第三层左边1个小正方形,
故选A

5.B

【解析】
由作图得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为等腰三角形,可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,由l1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> l2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,从而可得结论.
解:由作图得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为等腰三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∵∠
BCA150°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
l1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> l2
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选B

6.C

【解析】
利用已知得出数字个位数的变化规律进而得出答案.
解:∵21222423824162532,…,
尾数每4个一循环,
∵2022÷4
505……2
∴22022
的个位数字应该是:4
故选:C

7.A

【解析】
根据不等式kx+b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x的解集即为一次函数图象在正比例函数图象下方的自变量的取值范围求解即可
解:由函数图象可知不等式kx+b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x的解集即为一次函数图象在正比例函数图象下方的自变量的取值范围,
kx+b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x时,x的取值范围是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选A

8.C

【解析】
连接OAOE,设OEAB交于点P,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 得四边形ABDC是矩形,根据CD <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 切于点EOE <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的半径得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据边之间的关系得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,由勾股定理得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,进行计算可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即可得这种铁球的直径.
解:如图所示,连接OAOE,设OEAB交于点P
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形ABDC是矩形,
CD <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 切于点EOE <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的半径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
AB=CD=16cm
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,由勾股定理得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
则这种铁球的直径= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选C

9.C

【解析】
根据抛物线的开口方向向下即可判定;②先运用二次函数图像的性质确定abc的正负即可解答;③将点A的坐标代入即可解答;④根据函数图像即可解答;⑤运用作差法判定即可.
解:①由抛物线的开口方向向下,则a0,故①正确;
②∵
抛物线的顶点为P1m
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> b=-2a
a0
b0
抛物线与y轴的交点在正半轴
c0
abc0,故②错误;
③∵
抛物线经过点A21
∴1
a·22+2b+c,即4a+2b+c1,故③正确;
④∵
抛物线的顶点为P1m),且开口方向向下
x1时,yx的增大而减小,即④正确;
⑤∵
a0
at2+bt-a+b
=
at2-2at-a+2a
= at2-2at+a
=at2-2t+1
=
at-12≤0
at2+bta+b,则⑤正确
综上,正确的共有4个.
故答案为C

10.C

【解析】
如图所示,过点F <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> BCH,连接EH,可证明四边形CDFH是平行四边形,得到CH=DF=8CD=FH,则BH=4,从而可证四边形ABHE是平行四边形,得到AB=HE,即可推出当EFH三点共线时,EH+HF有最小值EFAB+CD有最小值EF,延长AEPQG,过点EETPQT,过点AALPQL,过点DDKPQK,证明四边形BEGC是平行四边形,∠EGT=∠BCQ=60°,得到EG=BC=12,然后通过勾股定理和解直角三角形求出ETTF的长即可得到答案.
解:如图所示,过点F <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> BCH,连接EH
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形CDFH是平行四边形,
CH=DF=8CD=FH
BH=4
BH=AE=4   
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形ABHE是平行四边形,
AB=HE
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
EFH三点共线时,EH+HF有最小值EFAB+CD有最小值EF
延长AEPQG,过点EETPQT,过点AALPQL,过点DDKPQK
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形BEGC是平行四边形,∠EGT=∠BCQ=60°
EG=BC=12
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
同理可求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
ALPQDKPQ
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∴△
ALO∽△DKO
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

11.

【解析】
根据算术平方根的定义,求数a的算术平方根,也就是求一个正数x,使得x2=a,则x就是a的算术平方根, 特别地,规定0的算术平方根是0.
∵2
2=4,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> =2.

12.3

【解析】
根据众数的定义:一组数据中出现次数最多的数据叫做这组数据的众数进行求解即可.
解:233435这组数据中,3出现了3次,出现的次数最多,
∴2
33435这组数据的众数为3
故答案为:3

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
先根据题意可以把ab看做是一元二次方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的两个实数根,利用根与系数的关系得到a+b=4ab=3,再根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 进行求解即可.
解:∵ab分别满足a2﹣4a+30b2﹣4b+30
可以把ab看做是一元二次方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的两个实数根,
a+b=4ab=3
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

14.-31

【解析】
根据“帥”和“马”的坐标建立正确的坐标系即可得到答案.
解:由题意可建立如下平面直角坐标系,
∴“
兵”的坐标是(-31),
故答案为:(-31).
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

15.2

【解析】
设点A的坐标为(m2m),根据OA的长度,利用勾股定理求出m的值即可得到点A的坐标,由此即可求出k
解:设点A的坐标为(m2m),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (舍去),
A的坐标为(12),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为:2

16. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
如图所示,过点EEFABF,先解直角三角形求出AFEF,从而求出BF,利用勾股定理求出BE的长,证明△ABD≌△BCE得到∠BAD=∠CBEAD=BE,再证明△BDP∽△ADB,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即可求出BPPD,从而求出AP,由此即可得到答案.
解:如图所示,过点EEFABF
∵△
ABC是等边三角形,
AB=BC,∠ABD=∠BAC=∠BCE=60°
CE=BD=2AB=AC=6
AE=4
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
BF=4
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵BD=CE
∴△
ABD≌△BCESAS),
∴∠
BAD=∠CBEAD=BE
又∵∠BDP=∠ADB
∴△
BDP∽△ADB
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∴△
ABP的周长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 2

【解析】
先根据同分母分式的减法计算法则化简,然后代值计算即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

18.(1)60108°
(2)150
(3)
树状图见解析, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)先根据A等级的人数和人数占比求出此次抽取的学生人数,即可求出a的值;用360度乘以C等级的人数占比即可求出C等级对应的圆心角度数;
2)用600乘以样本中A等级的人数占比即可得到答案;
3)先画树状图得到所有的等可能性的结果数,然后找到符合题意的结果数,最后依据概率计算公式求解即可.
(1)
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 人,
此次抽取的学生人数为60人,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C等级对应的圆心角度数为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为:60108°
(2)
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 人,
估计该校成绩为A等级的学生共有150人,
答:估计该校成绩为A等级的学生共有150人;
(3)
解:画树状图如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
由树状图可知一共有6种等可能性的结果数,其中抽到T1T2的结果数有2种,
恰好抽到T1T2的概率为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

19.(1)见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)先证明△DCFDCO得到DF=DOCF=CO,再由矩形的性质证明OC=OD,即可证明DF=CF=OC=OD
2)由全等三角形的性质得到∠CDO=∠CDF=60°OD=DF=6,即可证明△OCD是等边三角形,得到CD=OD=6,然后解直角三角形BCD求出BC的长即可得到答案.
(1)
解:在△DCF和△DCO中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∴△
DCF≌△DCOASA),
DF=DOCF=CO
四边形ABCD是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
DF=CF=OC=OD
(2)
解:∵△DCF≌△DCO
∴∠
CDO=∠CDF=60°OD=DF=6
又∵OD=OC
∴△
OCD是等边三角形,
CD=OD=6
四边形ABCD是矩形,
∴∠
BCD=90°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

20.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)先根据斜坡CF的坡比=13,求出CG的长,然后利用勾股定理求出CD的长即可;
2)如图所示,过点DDHABH,则四边形BHDG是矩形,BH=DG=30米,DH=BG,证明AB=BC,设AB=BC=x米,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 米, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 米,解直角三角形得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 据此求解即可.
1)解:∵斜坡CF的坡比=13,铅垂高度DG=30米,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 米,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 米;
2)解:如图所示,过点DDHABH,则四边形BHDG是矩形,∴BH=DG=30米,DH=BG,∵∠ABC=90°,∠ACB=45°,∴△ABC是等腰直角三角形,∴AB=BC,设AB=BC=x米,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 米, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 米,在RtADH中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 米. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

21.(1)2.5 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(3)
当小明离家2km时,他离开家所用的时间为12min37.5min

【解析】
1)根据函数图象结合路程=时间×速度进行求解即可;
2)分当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时和当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时两种情况讨论求解即可;
3)分当小明处在去体育馆的途中离家2km时,当小明从体育馆去商店途中离家2kn时两种情况讨论求解即可.
1)解:由函数图象可知小明在离家15分钟时到底体育馆,此时离家的距离为2.5km,∴小明家离体育馆的距离为2.5km,小明跑步的平均速度为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,故答案为:2.5 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
2)解:由函数图象可知当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,此时y是关于x一次函数,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,∴此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,综上所述, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
3)解:当小明处在去体育馆的途中离家2km时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;当小明从体育馆去商店途中离家2km时,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;综上所述,当小明离家2km时,他离开家所用的时间为12min37.5min

22.(1)PC与⊙O相切,理由见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)先证明∠ACB=90°,然后推出∠PCB=∠OCA,即可证明∠PCO=90°即可;
2)先证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,再证明△PBC∽△PCA,从而求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> AB=3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,最后证明△PBC∽△POD,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则CD=6,由此求解即可.
(1)
解:PC与⊙O相切,理由如下:
AB是圆O的直径,
∴∠
ACB=90°
∴∠
OCB+∠OCA=90°
OA=OC
∴∠
OCA=∠OAC
∵∠
PCB=∠OAC
∴∠
PCB=∠OCA
∴∠
PCB+∠OCB=∠OCA+∠OCB=90°,即∠PCO=90°
PC与⊙O相切;
(2)
解:∵∠ACB=90° <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∵∠
PCB=∠OAC,∠P=∠P
∴△
PBC∽△PCA
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
AB=6
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∴△
PBC∽△POD
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
CD=6
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

23.(1)0 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 4)或( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 4
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(4)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)根据交点和准线方程的定义求解即可;
2)先求出点P的纵坐标为4,然后代入到抛物线解析式中求解即可;
3)如图所示,过点BBDy轴于D,过点AAEy轴于E,证明△FDB∽△FHC,推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点B的纵坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,从而求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,证明△AEF∽△BDF,即可求出点A的坐标为( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ),再把点A的坐标代入抛物线解析式中求解即可;
4)如图,当E为靠近点F的黄金分割点的时候,过点MMNlN,则MN=MF
先证明△MNH是等腰直角三角形,得到NH=MN,设点M的坐标为(m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ),则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,然后根据黄金分割点的定义求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;同理可求当点E是靠近H的黄金分割点时△HME的面积.
(1)
解:由题意得抛物线y2x2的焦点坐标和准线l的方程分别为(0 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为:(0 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(2)
解:由题意得抛物线y <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x2的准线方程为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
P到准线l的距离为6
P的纵坐标为4
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
P的坐标为( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 4)或( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 4 );
(3)
解:如图所示,过点BBDy轴于D,过点AAEy轴于E
由题意得点F的坐标为F0 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> )直线l的解析式为:y=﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∴△
FDB∽△FHC
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
BC=2BF
CF=3BF
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B的纵坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (负值舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∴△
AEF∽△BDF
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
EF=2
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A的坐标为( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (负值舍去);
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(4)
解:如图,当E为靠近点F的黄金分割点的时候,过点MMNlN,则MN=MF
RtMNH中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∴∠
MHN=45°
∴△
MNH是等腰直角三角形,
NH=MN
设点M的坐标为(m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
HN=2
E是靠近点F的黄金分割点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
同理当E时靠近H的黄金分割点点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
综上所述, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

24.(1)86
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 6
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 6
(4)
OG的最小值为4,线段FP扫过的面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)由勾股定理即可求解;
2)连接OP,过点PPQOB于点Q,因为∠POB=45°,所以PQ=OQ,设PQ=OQ=x,则BQ=10-x,根据tanB的值,即可求得x的值,再利用勾股定理,即可求解;
3)令PA'OB于点D,由点E为线段OB的中点,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,利用折叠的性质、正切函数、勾股定理,即可求解;
4)当以点F为圆心,OF的长为半径画圆,与AB的交点即为点P,再将线段FP绕点F顺时针方向旋转60°得线段FG,此时OG最小,利用三角函数、等边三角形的判定与性质、扇形的面积公式,即可求解.
(1)
解:在RtOAB中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B的坐标为(86);
(2)
解:连接OP,过点PPQOB于点Q,如图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
∵∠
POB=45°
∴∠
OPQ=45°
∴∠
POB=∠OPQ
PQ=OQ
PQ=OQ=x,则BQ=10-x
RtOAB中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
RtBPQ中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
RtPOQ中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
RtAOP中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
P的坐标为( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 6);
(3)
解:令PA'OB于点D,如图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
E为线段OB的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
由折叠的性质,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
Rt <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
P的坐标为( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 6);
(4)
解:以点F为圆心,OF的长为半径画圆,与AB的交点即为点P,再将线段FP绕点F顺时针方向旋转60°得线段FG,连接OG,此时OG最小,如图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
由题可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是等边三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
OG的最小值为4
线段FP扫过的面积= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>