初中毕业升学数学考试
(课改)
一、填空题:本大题共12小题,每小题2分,共24分.
1.比较大小:
.
2.计算: .
3.已知
,则
的余角等于 .
4.投一枚均匀的正方体骰子,面朝上的点数是5的概率是 .
5.反比例函数的图象的一个分支如图1所示,
则另一个分支在第 象限.
6.方程的解是 .
7.正
边形的一个外角等于
,则
.
8.已知不等式组无解,则
的取值范围是 .
9.如图2的围棋盘放在平面直角坐标系内,黑棋的坐标为
,
那么白棋
的坐标是 .
10.如图3,中,
,
,
,则
.
11.若,
,且
,则
.
12.如图4,
,
为
的中点,
都是半径为3的的切线,
为切点,则
的长
为 .
二、选择题:本大题共8小题,每小题3分,共24分.在每小题给出的四个选项中,只有一项是符合题意的,请将你认为正确答案的序号填在题后的括号内.
13.方程的解是( )
A.
B.
C.或
D.
或
14.图5是一个正方体的展开图,将它折叠成正方体后,
“建”字的对面是( )
A.和 B.谐 C.社 D.会
15.为了做一个试管架,在长为的木板上钻3个小孔(如图6),每个小孔的直径为2cm,则
等于( )
A.cm B.
cm C.
cm D.
cm
16.哥哥身高1.68米,在地面上的影子长是2.1米,
同一时间测得弟弟的影子长1.8米,则弟弟身高是( )
A.1.44米 B.1.52米
C.1.96米 D.2.25米
17.某超市购进了一批不同价格的运动鞋,根据近几年统计的平均数据,运动鞋单价为40元,35元,30元,25元的销售百分率分别为,
,
,
.要使该超市销售运动鞋收入最大,该超市应多购单价为( )的运动鞋.
A.40元 B.35元 C.30元 D.25元
18.下列等式必定成立的是( )
A. B.
C. D.
19.如图7,
是菱形
的对角线
的交点,
分别是
的中点.下列结论:①
;②四边形
是中心对称图形;③
是轴对称图形;④
.其中错误的结论有 .
A.1个 B.2个 C.3个 D.4个
20.如图8,直线
相交于点
,
,半径为1cm的
的圆心在射线
上,且与点
的距离为6cm.如果
以1cm/s的速度沿由
向
的方向移动,那么( )秒种后
与直线
相切.
A.4 B.8
C.4或6 D.4或8
三、解答题:本大题共8小题,满分共72分.解答应写出文字说明,证明过程或演算步骤.
21.(本题满分7分)
计算:.
22.(本题满分7分)
化简:.
23.(本题满分8分)
如图9,相交于
,现给出如下三个论断:
①;②
;③
.
请你选择其中两个论断为条件,另外一个论断为结论,构造一个命题.
(1)在构成的所有命题中,真命题有 个.
(2)在构成的真命题中,请你选择一个加以证明.
你选择的真命题是:(用序号表示).
24.(本题满分8分)
| 14岁 | 15岁 | 16岁 |
频数记录 | 正正正 | 正正正正正 | 正正正 |
频数 | 15 | 10 | |
频率 | 0.5 |
右表是某班学生年龄统计表.
(1)请你把表中未填的项目补充完整;
(2)从表中可以看出,众数是 ,
中位数是 ,平均数是 ;
(3)请你根据统计表,在图10中画出该
班学生年龄统计直方图(要求标出数字).
25.(本题满分8分)
如图11,梯形中,
,
是中位线,
于
,
于
,梯形的高
.沿着
分别把
,
剪开,然后按图中箭头所指方向,分别绕着点
旋转
,将会得到一个什么样的四边形?简述理由.
26.(本题满分10分)
福林制衣厂现有24名制作服装工人,每天都制作某种品牌衬衫和裤子,每人每天可制作衬衫3件或裤子5条.
(1)若该厂要求每天制作的衬衫和裤子数量相等,则应安排制作衬衫和裤子各多少人?
(2)已知制作一件衬衫可获得利润30元,制作一条裤子可获得利润16元,若该厂要求每天获得利润不少于2100元,则至少需要安排多少名工人制作衬衫?
27.(本题满分12分)
已知抛物线与直线
相交于点
.
(1)求抛物线的解析式;
(2)请问(1)中的抛物线经过怎样的平移就可以得到的图象?
(3)设抛物线上依次有点
,其中横坐标依次是
,纵坐标依次为
,试求
的值.
28.(本题满分12分)
如图12,是
的内接三角形,直径
,交
于
,
,
的延长线相交于
.
(1)求证:;
(2)若,试求
的半径;
(3)当
是什么类型的弧时,
的外心在
的外部、内部、一边上?(只写结论,不用证明)
初中毕业数学升学考试
课改 参考答案
一、填空题
1.> 2. 3.
4.
5.四 6.
7.18 8.
9.
10.
11.
12.
二、选择题
13.D 14.C 15.C 16.A 17.B 18.C
19.A 20.D
三、解答题
21.解:原式····················································································· 5分
.······································································································ 7分
22.解法一:原式···································································· 2分
························································································· 4分
.···························································································· 7分
解法二:原式········································································ 2分
·············································································· 4分
.······················································································· 7分
解法三:原式················································································ 4分
.··································································································· 7分
23.(1)2····················································································································· 2分
(2)你选择的真命题是:······································································· 4分
证明:在和
中,
,
.·································································································· 6分
.··············································································································· 8分
选择命题二:······························································································· 4分
证明:在和
中,
,
,
.······································································································ 6分
.················································································································· 8分
24.解:(1)
| 14岁 | 15岁 | 16岁 |
频数记录 | 正正正 | 正正正 正正 | 正正 |
频数 | 15 | 25 | 10 |
频率 | 0.3 | 0.5 | 0.2 |
(2)15岁,15岁,14.9岁;
(3)
25.解:将会得到一个正方形,理由如下:··································································· 1分
,
.············································································································· 2分
是梯形
的中位线,
,
.·············································································································· 4分
梯形的高
,
梯形的高
.··································································································· 5分
设绕点
旋转
后点
落在
处,
绕点
旋转
后,点
落在
处则
,
在
所在的直线上.
是梯形
的高.························································································· 6分
,
.······················································ 7分
四边形
是正方形.······················································································ 8分
26.解:(1)设应安排名工人制作衬衫,依题意,得················································· 1分
.·········································································································· 3分
解之,得.········································································································· 4分
.
答:应安排15名工人制作衬衫,9名工人制作裤子.···················································· 5分
(2)设应安排名工人制作衬衫,依题意,得····························································· 6分
.··············································································· 8分
解之,得.······································································································· 9分
答:至少应安排18名工人制作衬衫.·········································································· 10分
27.解:(1)点
在直线
上,
.····································································································· 1分
把代入
,
得.求得
.·················································································· 3分
抛物线的解析式是
.······································································· 4分
(2).
顶点坐标为
.···································································································· 6分
把抛物线
向左平移3个单位长度得到
的图象,再把
的图象向下平移1个单位长度得到
的图象.······························································································· 7分
(3)由题意知,的横坐标是连续偶数,所以
的横坐标是
,纵坐标为
所对应的纵坐标依次是
.············································································································· 9分
····················································································· 10分
.········································································· 12分
28.(1)证明:连结.··························································································· 1分
,
.
.················································································· 2分
,
.
.··································································································· 3分
又,
.········································································································ 4分
(2)解:连结,则
.·································································· 5分
,
.········································································································ 6分
,
.································································································· 7分
.············································································································· 8分
.
,即
的半径为2.··················································································· 9分
(3)解:当是劣弧时,
的外心在
的外部.······························· 10分
当是半圆时,
的外心在
的边上.··············································· 11分
当是优弧时,
的外心在
的内部.··············································· 12分