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【327775】2022年四川省内江市中考数学真题

时间:2025-01-20 20:14:30 作者: 字数:23930字
简介:

绝密·启用前

2022年四川省内江市中考数学真题

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.﹣6的相反数是(  )
A
.﹣6
B
.﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
6
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

2.4S店今年15月新能源汽车的销量(辆数)分别如下:2533363140,这组数据的平均数是(  )
A
34
B
33
C
32.5
D
31

3.下列运算正确的是(  )
A
a2+a3a5
B.(a32a6
C.(ab2a2b2
Dx6÷x3x2

4.20222月第24届冬季奥林匹克运动会在我国北京成功举办,以下是参选的冬奥会会徽设计的部分图形,其中既是轴对称图形又是中心对称图形的是(  )
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

5.下列说法错误的是(  )
A
.打开电视机,中央台正在播放发射神舟十四号载人飞船的新闻,这是随机事件
B
.要了解小王一家三口的身体健康状况,适合采用抽样调查
C
.一组数据的方差越小,它的波动越小
D
.样本中个体的数目称为样本容量

6.如图是正方体的表面展开图,则与“话”字相对的字是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
A
.跟
B
.党
C
.走
D
.听

7.如图,在ABCD中,已知AB12AD8,∠ABC的平分线BMCD边于点M,则DM的长为(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
A
2
B
4
C
6
D
8

8.如图,数轴上的两点AB对应的实数分别是ab,则下列式子中成立的是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
A
1﹣2a1﹣2b
B.﹣a<﹣b
Ca+b0
D
|a|﹣|b|0

9.如图,在平面直角坐标系中,点BCEy轴上,点C的坐标为(01),AC2Rt△ODERt△ABC经过某些变换得到的,则正确的变换是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
A
.△ABC绕点C逆时针旋转90°,再向下平移1个单位
B
.△ABC绕点C顺时针旋转90°,再向下平移1个单位
C
.△ABC绕点C逆时针旋转90°,再向下平移3个单位
D
.△ABC绕点C顺时针旋转90°,再向下平移3个单位

10.如图,在平面直角坐标系中,点Mx轴正半轴上一点,过点M的直线ly轴,且直线l分别与反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的图象交于PQ两点.若SPOQ15,则k的值为(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
A
38
B
22
C
.﹣7
D
.﹣22

11.如图,正六边形ABCDEF内接于⊙O,半径为6,则这个正六边形的边心距OM <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长分别为(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
A
4 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> π
C
2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

12.如图,抛物线yax2+bx+cx轴交于两点(x10)、(20),其中0x11.下列四个结论:①abc0;②a+b+c0;③2ac0;④不等式ax2+bx+c>﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x+c的解集为0xx1.其中正确结论的个数是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
A
4
B
3
C
2
D
1

评卷人

得分




二、填空题

13.函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,自变量 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的取值范围是 .

14.如图,在⊙O中,∠ABC=50°,则∠AOC等于_____
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

15.对于非零实数ab,规定ab <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,若(2x﹣1)⊕21,则x的值为 _____

16.勾股定理被记载于我国古代的数学著作《周髀算经》中,汉代数学家赵爽为了证明勾股定理,创制了一幅如图①所示的“弦图”,后人称之为“赵爽弦图”.图②由弦图变化得到,它是由八个全等的直角三角形拼接而成.记图中正方形ABCD、正方形EFGH、正方形MNKT的面积分别为S1S2S3.若正方形EFGH的边长为4,则S1+S2+S3_____
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

17.分解因式:a4﹣3a2﹣4_____

18.如图,在平面直角坐标系中,一次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的图象经过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 且与函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的图象交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .若一次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的增大而增大,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的取值范围是____
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

19.已知x1x2是关于x的方程x2﹣2x+k﹣10的两实数根,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x12+2x2﹣1,则k的值为 _____

20.如图,矩形ABCD中,AB6AD4,点EF分别是ABDC上的动点,EFBC,则AF+CE的最小值是 _____
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

评卷人

得分




三、解答题

21.1)计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)先化简,再求值:( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ÷ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,其中a=﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +4

22.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,EF是对角线BD上两个点,且满足BE=DF
1)求证:△ABE≌△CDF
2)求证:四边形AECF是平行四边形.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

23.为让同学们了解新冠病毒的危害及预防措施,某中学举行了“新冠病毒预防”知识竞赛.数学课外活动小组将八(1)班参加本校知识竞赛的40名同学的成绩(满分为100分,得分为正整数且无满分,最低为75分)分成五组进行统计,并绘制了下列不完整的统计图表:

分数段

频数

频率

74.5﹣79.5

2

0.05

79.5﹣84.5

8

n

84.5﹣89.5

12

0.3

89.5﹣94.5

m

0.35

94.5﹣99.5

4

0.1


 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
表中m   n   
(2)
请补全频数分布直方图;
(3)
本次知识竞赛中,成绩在94.5分以上的选手,男生和女生各占一半,从中随机确定2名学生参加颁奖,请用列表法或树状图法求恰好是一名男生和一名女生的概率.

24.如图所示,九(1)班数学兴趣小组为了测量河对岸的古树AB之间的距离,他们在河边与AB平行的直线l上取相距60mCD两点,测得∠ACB15°,∠BCD120°,∠ADC30°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
求河的宽度;
(2)
求古树AB之间的距离.(结果保留根号)

25.如图,△ABC内接于⊙OAB是⊙O的直径,⊙O的切线PCBA的延长线于点POFBCAC于点E,交PC于点F,连接AF
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
判断直线AF与⊙O的位置关系并说明理由;
(2)
若⊙O的半径为6AF2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,求AC的长;
(3)
在(2)的条件下,求阴影部分的面积.

26.为贯彻执行“德、智、体、美、劳”五育并举的教育方针,内江市某中学组织全体学生前往某劳动实践基地开展劳动实践活动.在此次活动中,若每位老师带队30名学生,则还剩7名学生没老师带;若每位老师带队31名学生,就有一位老师少带1名学生.现有甲、乙两型客车,它们的载客量和租金如表所示:


甲型客车

乙型客车

载客量(人/辆)

35

30

租金(元/辆)

400

320


学校计划此次劳动实践活动的租金总费用不超过3000元.
(1)
参加此次劳动实践活动的老师和学生各有多少人?
(2)
每位老师负责一辆车的组织工作,请问有哪几种租车方案?
(3)
学校租车总费用最少是多少元?

27.如图,在矩形ABCD中,AB6BC4,点MN分别在ABAD上,且MNMC,点ECD的中点,连接BEMC于点F
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
FBE的中点时,求证:AMCE
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 2,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值;
(3)
MNBE,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值.

28.如图,抛物线yax2+bx+cx轴交于A(﹣40),B20),与y轴交于点C02).
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
求这条抛物线所对应的函数的表达式;
(2)
若点D为该抛物线上的一个动点,且在直线AC上方,求点D到直线AC的距离的最大值及此时点D的坐标;
(3)
P为抛物线上一点,连接CP,直线CP把四边形CBPA的面积分为15两部分,求点P的坐标.

参考答案

1.C

【解析】
根据相反数的意义,即可解答.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的相反数是6
故选:C

2.B

【解析】
根据算术平均数的计算方法进行计算即可.
解:这组数据的平均数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 33(辆),
故选:B

3.B

【解析】
根据合并同类项法则,幂的乘方和同底数幂的除法法则,完全平方公式,进行判断即可.
A.
a2a3不是同类项,不能合并,故A不符合题意;
B.
a32a6,故B符合题意;
C.
ab2a2﹣2ab+b2,故C不符合题意;
D.
x6÷x3x6﹣3x3,故D不符合题意.
故选:B

4.C

【解析】
根据轴对称图形和中心对称图形的定义进行逐一判断即可.
A.
不是轴对称图形,也不是中心对称图形,故A错误;
B.
不是轴对称图形,也不是中心对称图形,故B错误;
C.
既是轴对称图形,也是中心对称图形,故C正确;
D.
不是轴对称图形,也不是中心对称图形,故D错误.
故选:C

5.B

【解析】
根据随机事件的定义、全面调查的意义、方差的意义以及样本容量的定义进行判定即可.
解:A.打开电视机,中央台正在播放发射神舟十四号载人飞船的新闻,这是随机事件,故A选项不符合题意;
B
.要了解小王一家三口的身体健康状况,适合采用全面调查调查,故B选项符合题意;
C
.一组数据的方差越小,它的波动越小,故C选项不符合题意;
D
.样本中个体的数目称为样本容量,故D选项不符合题意.
故选:B

6.C

【解析】
根据正方体表面展开图的特征进行判断即可.
解:由正方体表面展开图的“相间、Z端是对面”可知,
话”与“走”是对面,
故答案为:C

7.B

【解析】
根据平行四边形的性质及角平分线的性质可得∠CBM=∠CMB,利用等边对等角即可得MCBC8,进而可求解.
解:∵四边形ABCD是平行四边形,
CDAB12BCAD8ABCD
∴∠
ABM=∠CMB
BM是∠ABC的平分线,
∴∠
ABM=∠CBM
∴∠
CBM=∠CMB
MCBC8
DMCDMC12﹣84
故选:B

8.A

【解析】
根据数轴得出ab,根据不等式的性质对四个选项依次分析即可得到答案.
解:由题意得:ab
∴﹣2
a>﹣2b
∴1﹣2
a1﹣2b
∴A
选项的结论成立;
ab
∴﹣
a>﹣b
∴B
选项的结论不成立;
∵﹣2
a<﹣12b3
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
a+b0
∴C
选项的结论不成立;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
∴D
选项的结论不成立.
故选:A

9.D

【解析】
观察图形可以看出,Rt△ABC通过变换得到Rt△ODE,应先旋转然后平移即可.
解:根据图形可以看出,△ABC绕点C顺时针旋转90°,再向下平移3个单位可以得到△ODE
故选:D

10.D

【解析】
设点Pab),Qa <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ),则OMaPMbMQ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则PQPM+MQ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再根据ab8SPOQ15,列出式子求解即可.
解:设点Pab),Qa <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ),则OMaPMbMQ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
PQPM+MQ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
P在反比例函数y <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的图象上,
ab8
SPOQ15
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> PQOM15
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ab <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )=15
abk30
∴8﹣
k30
解得:k=﹣22
故选:D

11.D

【解析】
连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,证出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是等边三角形,根据勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再由弧长公式求出弧 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长即可.
解:连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 六边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为正六边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为等边三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:D

12.C

【解析】
根据函数图象可得出abc的符号即可判断①,当x1时,y0即可判断②;根据对称轴为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> a0可判断③;y1ax2+bx+c <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 数形结合即可判断④.
解:∵抛物线开口向上,对称轴在y轴右边,与y轴交于正半轴,
a0b0c0
abc0
∴①
正确.
x1时,y0
a+b+c0
∴②
错误.
抛物线yax2+bx+cx轴交于两点(x10)、(20),其中0x11
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
∴2
ac0
∴③
正确;
如图:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
y1ax2+bx+c <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由图值,y1y2时,x0xx1
故④错误.
故选:C

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
求函数自变量的取值范围,就是求函数解析式有意义的条件,二次根式有意义的条件是:被开方数为非负数.
依题意,得x-3≥0
解得:x≥3

14.100°

【解析】
试题在同圆或等圆中,相等的弧所对的圆心角等于圆周角度数的2.根据题意可得:∠AOC=2∠ABC=2×50°=100°.

15. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
根据题意列出方程,解方程即可求解.
解:由题意得:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 1
等式两边同时乘以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
经检验,x <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是原方程的根,
x <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

16.48

【解析】
设八个全等的直角三角形的长直角边为a,短直角边是b,然后分别求出S1S2S3,即可得到答案.
解:设八个全等的直角三角形的长直角边为a,短直角边是b,则:
S1=(a+b2S24216S3=(ab2
且:a2+b2EF216
S1+S2+S3=(a+b2+16+ab22a2+b2+16
2×16+16
48
故答案为:48

17.a2+1)(a+2)(a﹣2

【解析】
首先利用十字相乘法分解为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,然后利用平方差公式进一步因式分解即可.
解:a4﹣3a2﹣4
=(a2+1)(a2﹣4
=(a2+1)(a+2)(a﹣2),
故答案为:(a2+1)(a+2)(a﹣2).

18. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
分别求出过点P,且平行于x轴和y轴时对应的m值,即可得到m的取值范围.
PQ平行于x轴时,点Q的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
PQ平行于y轴时,点Q的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
一次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的增大而增大,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的取值范围是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

19.2

【解析】
根据一元二次方程根与系数的关系以及解的定义得到x1+x22x1x2k﹣1x12﹣2x1+k﹣10,再根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x12+2x2﹣1,推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 4﹣k,据此求解即可.
解:∵x1x2是关于x的方程x2﹣2x+k﹣10的两实数根,
x1+x22x1x2k﹣1x12﹣2x1+k﹣10
x122x1k+1
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x12+2x2﹣1
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 2x1+x2)﹣k
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 4﹣k
解得k2k5
k2时,关于x的方程为x2﹣2x+10Δ≥0,符合题意;
k5时,关于x的方程为x2﹣2x+40Δ0,方程无实数解,不符合题意;
k2
故答案为:2

20.10

【解析】
延长BCG,使CGEF,连接FG,证明四边形EFGC是平行四边形,得出CEFG,得出当点AFG三点共线时,AF+CE的值最小,根据勾股定理求出AG即可.
解:延长BCG,使CGEF,连接FG
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> EFCG
四边形EFGC是平行四边形,
CEFG
AF+CEAF+FG
当点AFG三点共线时,AF+CE的值最小为AG
由勾股定理得,AG <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 10
AF+CE的最小值为10
故答案为:10

21.12;(2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)首先代入特殊角的三角函数值,进行乘方、绝对值运算,再进行乘法和加法运算;
2)首先把分式化简,再代入ab的值计算.
解:(1)原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +2﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2
2)原式=[ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ]• <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
a=﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +4时,
原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

22.证明见解析

【解析】
1)根据平行四边形的性质可以得到AB//CDAB=CD,再证明角相等,用SAS证明两个三角形全等即可.
2)用(1)中全等三角形的结论我们得到边相等,角相等,再去证明平行.用一组对边平行且相等证明四边形是平行四边形.
证明:(1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 四边形ABCD是平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> AB//CDAB=CD
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)由(1)可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> AE//CF
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 四边形AECF是平行四边形.

23.(1)140.2
(2)
见解析
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)根据总数为40,频率为0.35,求出m,根据频数为8,总数为40,求出频率n
2)根据89.5﹣94.5的频数为14,补全频数分布直方图即可;
3)先根据题意画出树状图,然后根据概率公式进行计算即可.
(1)
解:m40×35%14n8÷400.2
故答案为:140.2
(2)
补全频数分布直方图如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(3)
成绩在94.5分以上的选手有4人,男生和女生各占一半,
∴2
名是男生,2名是女生,
画树状图如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
共有12种等可能的结果,其中确定的2名学生恰好是一名男生和一名女生的结果有8种,
确定的2名学生恰好是一名男生和一名女生的概率为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

24.(1)30 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +30)米;
(2)20
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 米.

【解析】
1)过点AAEl于点E,设CE=x,在RtADE中可表示出DE,在RtACE中可表示出AE,通过解直角三角形ADE求出x即可;
2)过点BBFl,垂足为F,继而得出CE的长,在RtBCF中,求出CF,继而可求出AB
(1)
解:过点AAEl,垂足为E
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
CEx米,
CD60米,
DECE+CD=(x+60)米,
∵∠
ACB15°,∠BCD120°
∴∠
ACE180°﹣∠ACB﹣∠BCD45°
RtAEC中,AECEtan45°x(米),
RtADE中,∠ADE30°
tan30° <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
x30 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +30
经检验:x30 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +30是原方程的根,
AE=(30 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +30)米,
河的宽度为(30 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +30)米;
(2)
过点BBFl,垂足为F
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
CEAEBF=(30 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +30)米,ABEF
∵∠
BCD120°
∴∠
BCF180°﹣∠BCD60°
RtBCF中,CF <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> =(30+10 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )米,
ABEFCECF30 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> +30﹣30+10 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )=20 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (米),
古树AB之间的距离为20 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 米.

25.(1)直线AF与⊙O相切.理由见解析
(2)6
(3)18
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ﹣6π

【解析】
1)连接OC,证明△AOF≌△COFSAS),由全等三角形的判定与性质得出∠OAF=∠OCF=90°,由切线的判定可得出结论;
2)由直角三角形的性质求出∠AOF=30°,可得出AE= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> OA=3,则可求出答案;
3)证明△AOC是等边三角形,求出∠AOC=60°OC=6,由三角形面积公式和扇形的面积公式可得出答案.
(1)
直线AF与⊙O相切.
理由如下:连接OC
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
PC为圆O切线,
CPOC
∴∠
OCP90°
OFBC
∴∠
AOF=∠B,∠COF=∠OCB
OCOB
∴∠
OCB=∠B
∴∠
AOF=∠COF
AOFCOF中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
∴△
AOF≌△COFSAS),   
∴∠OAF=∠OCF90°
AFOA
又∵OA为圆O的半径,
AF为圆O的切线;
(2)
∵△
AOF≌△COF
∴∠
AOF=∠COF
OAOC
EAC中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
∵∠
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
∴∠
AOF30°   
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(3)
ACOA6OCOA
∴△
AOC是等边三角形,
∴∠
AOC60°OC6
∵∠
OCP90°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
SOCP <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
阴影部分的面积=SOCPS扇形AOC <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

26.(1)参加此次劳动实践活动的老师有8人,参加此次劳动实践活动的学生有247
(2)
一共有3种租车方案:租甲型客车3辆,租乙型客车5辆或租甲型客车4辆,租乙型客车4辆或租甲型客车5辆,租乙型客车3
(3)
学校租车总费用最少是2800元.

【解析】
1)设参加此次劳动实践活动的老师有x人,根据参加实践活动的学生人数的两种不同表示方法作为等量关系列方程;
2)首页判断车辆总数为8,设租甲型客车m辆,列出不等式组求出整数解即可;
3)列出函数解析式w80m+2560,结合自变量取值范围求出最少总费用.
(1)
设参加此次劳动实践活动的老师有x人,参加此次劳动实践活动的学生有(30x+7)人,
根据题意得:30x+731x﹣1
解得x8
∴30
x+730×8+7247
答:参加此次劳动实践活动的老师有8人,参加此次劳动实践活动的学生有247人;
(2)
师生总数为247+8255(人),
每位老师负责一辆车的组织工作,
一共租8辆车,
设租甲型客车m辆,则租乙型客车(8﹣m)辆,
根据题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得3≤m≤5.5
m为整数,
m可取345
一共有3种租车方案:租甲型客车3辆,租乙型客车5辆或租甲型客车4辆,租乙型客车4辆或租甲型客车5辆,租乙型客车3辆;
(3)
设租甲型客车m辆,则租乙型客车(8﹣m)辆,
由(2)知:3≤m≤5.5
设学校租车总费用是w元,
w400m+3208﹣m)=80m+2560
∵80
0
wm的增大而增大,
m3时,w取最小值,最小值为80×3+25602800(元),
答:学校租车总费用最少是2800元.

27.(1)见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
(1)
根据矩形的性质,证明△BMF≌ △ECF,得BMCE,再利用点ECD的 中点,即可证明结论;
(2)
利用△BMF∽△ECF,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,从而求出BM的长,再利用△ANM∽△BMC ,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,求出AN的长,可得答案;
(3)
首先利用同角的余角相等得 CBFCMB,则tan∠CBFtan∠CMB,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可得BM的长,由(2)同理可得答案.
(1)
证明:∵FBE的中点,
BFEF
四边形ABCD是矩形,
ABCDABCD
∴∠BMF=∠ECF
∵∠
BFM=∠EFC
∴△
BMF≌△ECFAAS),
BMCE
ECD的中点,
CE <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> CD
ABCD
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
AMCE
(2)
∵∠
BMF=∠ECF,∠BFM=∠EFC
∴△
BMF∽△ECF
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
CE3
BM <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
AM <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
CMMN
∴∠
CMN90°
∴∠
AMN+∠BMC90°
∵∠
AMN+∠ANM90°
∴∠
ANM=∠BMC
∵∠
A=∠MBC
∴△
ANM∽△BMC
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
DNADAN4﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(3)
MNBE
∴∠
BFC=∠CMN
∴∠
FBC+∠BCM90°
∵∠
BCM+∠BMC90°
∴∠
CBF=∠CMB
∴tan∠
CBFtan∠CMB
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由(2)同理得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得:AN <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
DNADAN4﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

28.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,点D的坐标为(﹣22);
(3)
P的坐标为(6,﹣10)或(﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ).

【解析】
1)运用待定系数法即可解决问题;
2)过点DDHABH,交直线AC于点G,过点DDEACE,可用待定系数法求出直线AC的解析式,设点D的横坐标为m,则点G的横坐标也为m,从而可以用m的代数式表示出DG,然后利用 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可得出关于m的二次函数,运用二次函数的最值即可解决问题;
3)根据SPCBSPCA= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可求解.
(1)
抛物线yax2+bx+cx轴交于A(﹣40),B20),与y轴交于点C02).
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
抛物线的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
2)过点DDHABH,交直线AC于点G,过点DDEACE,如图.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
设直线AC的解析式为ykx+t
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
直线AC的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
设点D的横坐标为m,则点G的横坐标也为m
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
DEACDHAB
∴∠
EDG+∠DGE=∠AGH+∠CAO90°
∵∠
DGE=∠AGH
∴∠
EDG=∠CAO
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
m=﹣2时,点D到直线AC的距离取得最大值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
即点D的坐标为(﹣22);
(3)
如图,设直线CPx轴于点E
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
直线CP把四边形CBPA的面积分为15两部分,
又∵SPCBSPCA <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
EBAE1551
AE51
即点E的坐标为(10)或(﹣30),
将点E的坐标代入直线CP的表达式:ynx+2
解得:n=﹣2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故直线CP的表达式为:y=﹣2x+2y <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x+2
联立方程组 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得:x6或﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (不合题意值已舍去),
故点P的坐标为(6,﹣10)或(﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,﹣ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1005/" title="内江" class="c1" target="_blank">内江</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ).