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绝密★启用前
2024 年中考押题预测卷【江苏无锡卷】
数 学
一、选择题(本大题共10小题,每小题3分,共30分,在每小题所给出的四个选项中,恰有一项是符合
题目要求的,请将正确选项前的字母代号填涂在答题卡相应位置上).
1 2 3 4 5 6 7 8 9 10
A D B D A C D A A A
二、填空题(本大题共8小题,每小题3分,共24分,请把答案填写在答题卡相应位置上)
11. 12. 13.1 14.2
15.B 16 17. 18. / /
三、解答题(本大题共10小题,共96分,请在答题卡指定区域内作答,解答时应写出文字说明、证明过
程或演算步骤)
19.(9分)
【解析】解:(1)
;················································4分
(2)
···············································9分
20.(9分)
【解析】(1) , , ,
,
∴ ,
∴ , ;···············································4分
(2) ,
解不等式①,得 ,
解不等式②,得 ,∴不等式组的解集为 .···············································9分
21.(9分)
【解析】(1)证明:如图,连接 交 于点O,
∵四边形 是平行四边形,
∴ ,
∵ ,
∴ ,
∴ ,
∵ ,
∴四边形BEDF是平行四边形;···············································4分
(2)解:∵ ,
∴ ,
∵ , ,
∴ ···············································9分
22.(9分)
【解析】(1)用树状图表示为:
由图可知,共有4种等可能结果,其中P、Q间没有电流通过的只有1种,有电流通过的有3种,
∴ 之间电流通过的概率是 ;····································5分
(2)画树状图得:
由图可知,共有8种等可能结果,其中没有电流通过的只有1种,有电流通过的有7种,∴ 之间电流通过的概率是 .
故答案为: .····································9分
23.(10分)
【解析】(1)由题意得, ,
.
故答案为:5;····································2分
(2)解:统计图中B组对应扇形的圆心角为 ,
故答案为:144;····································4分
(3)解:由题意可知,阅读时间在 范围内的数据的众数是45,调查的20名同学课外阅读时间
的中位数是 .
故答案为:45, ;····································6分
(4)解: (人),
答:估计全校800名同学课外阅读时间不少于 的人数大约为480人.··································10分
24.(10分)
【解析】(1)如图所示,过点M作 的垂线,交 于O,以点O为圆心, 为半径画圆,则圆O即
为所求;····································3分
如图所示,过点O作 于N,
∵ 平分 , ,
∴ ,
∴射线 与 相切;····································6分
(2)解:∵ 和 为 的切线,
∴ , , ,
∴ ,
∴ 和 都是等腰直角三角形,
∴ ,即 ,∴ 的劣弧 与 所围成图形的面积
.
故答案为: .····································10分
25.(10分)
【解析】(1)证明:连接 ,如图,
是 的平分线,
,
,
为 的直径,
,
,
,
,
为 的半径,
直线 是 的切线;····································4分
(2)解: 为 的直径,
, ,
, ,,
,····································6分
的平分线 交 于点 ,
,
,
,····································8分
过点 作 于点 ,,
,
,
.····································10分
26.(10分)
【解析】(1)设 与 的函数表达式为 ,
把 和 分别代入 得:
,
解得: ,
∴ 与 的函数表达式为 ;····································4分
(2)解:当 时, ,····································5分
∵ ,
∴ 随 的增大而减小,
∴当 时, ;····································6分
当 时, ,····································7分
∵ 不在 范围内,当 时, 随 的增大而减小,
∴当 时, ;····································9分
综上述,第 天时,当天的销售利润最大,最大销售利润是 元.····································10分
27.(10分)
【解析】(1)① 四边形 是矩形,
, ,
由折叠知, , ,
, ,
在 和 中,,
,
, ,
设 ,则 , ,
在 中,由勾股定理得: ,
即 ,
解得: ,
则 ;····································2分
②如图,连接 交 于点 ,过点 作 于点 ,
,
(对顶角),
,
,
, ,
则 ,
, (对顶角),
,
,
,
,
,,
,
;····································6分
(2)当 落在直线 上面时,如图,过 作 于 ,
, ,
,
,
又 ,
,
由翻折可知 ,
在 中, ,
,
又 ,
在 中, ,
此时只要 ,点 在 边上,
;
当 落在直线 下面时,如图,过 作 于 ,同理可得, ,
在 中, , , ,
,
,
,
在 中, ,
此时要 在 边上,则 即可,即 ,
综上, .····································10分
28.(10分)
【解析】(1)由题可得: , ,
当 时,总有 ,
,
整理得: ,
,
,
,
;····································2分
(2)解:①注意到抛物线 最大值和开口大小不变, 只影响图象左右平移,
下面考虑满足题意的两种临界情况:
当抛物线 过点 时,如图1所示,
,
此时, , ,解得 或 (舍去);当抛物线 过点 时,如图2所示,
,
此时, , ,
解得: 或 (舍去),
综上所述, ;····································4分
②同①考虑满足题意的临界情形:
当抛物线 过点 时,如图3所示,
,
此时, , ,解得: 或 (舍去),·······················5分
当抛物线 过点 时,如图4所示,
,
此时, , ,解得 或 (舍去),····························6分综上所述, ,
如图 ,由圆的性质可得,点 在线段 的垂直平分线上,
,
,
解得: , ,
,
,
,
设 ,
,
,
,
,
,
,即 ,····································8分
,
,即 ,
,
.····································10分