2007 年四川省雅安市中考数学真题及答案
本试卷分为第 I 卷(选择题)和第 II 卷(非选择题)两部分,第 I 卷 1 至 2 页,第 II
卷 3 至 8 页.全卷满分 120 分,考试时间 120 分钟.
第 I 卷(选择题 共 36 分)
注意事项:
1.在答第 I 卷之前,考生务必将自己的姓名、准考证号、考试科目等填涂在机读卡上.
2.每小题选出答案后,用 2B 或 3B 铅笔把机读卡上对应题目的答案标号涂黑,如需改动,
用橡皮擦擦干净后,再选涂其它答案,不能答在试卷上.
3.考试结束后,由监考人员将本试卷和机读卡一并收回.
一、选择题(本大题共 12 个小题,每小题 3 分,共 36 分)每小题的四个选项中,有且仅
有一个是正确的.
1. 8 的立方根是(
)
A. 2 2
B. 2
C.
32 2
D.
3 2
2.下列运算正确的是(
)
A. 2
a a
3
5
a
B. 2 3
)a
(
5
a
C.
6
2
a
a
3
a
D. 5
a
5
a
10
a
3.下列右图是由 5 个相同大小的正方体搭成的几何体,则它的俯视图在 A、B、C、D 中的选
项是(
)
A.
B.
C.
4.若是直角三角形式一个锐角,sin
3 cos
,则
D.
2
sin
3 题图
2sin
2
cos
cos
(
)
A.3 2 3
B.
1 2 3
2
5.已知二次函数
y
kx
2 6
x
C. 2 2 3
D. 3
,若 k 在数组{ 3
3
, , ,,,, 中随机取一个,则所得
11 2 3 4}
2
抛物线的对称轴在直线 1x 的右方时的概率为(
)
B.
2
7
C.
4
7
A.
1
7
D.
5
7
6.在 ABC△
中, D E, 分别是 AB AC, 边上的中点,则
S
△
ADE
:
S
四边形
DBCE
(
)
A.
3
4
B.
1
4
C.
2
5
7.如图是坐标系的一部分,若 M 位于点 (2
D.
1
3
2), 上, N 位于
点 (4
2), 上,则G 位于点(
)上.
A.(1 3),
B.(11),
C.(0 1),
D.( 11) ,
G
M N
)
D.675m2
C.650m2
B.625m2
8.为搞好环保,某公司准备修建一个长方体的污水处理池,池底矩形的周长为 100m,则池
底的最大面积是(
A.600m2
9.如图,在平行四边形 ABCD 中, DE 是 ADC
F 是 AB 的中点,
(
)
A. 4 :1: 2
C.3:1: 2
10.已知不等式 (
B. 4 :1:3
D.5:1: 2
1)
2
x
a
的平分线,
:
x ,则(
AD ,则 :
AE EF BE 为
的解集是
AB ,
6
EF
)
C
D
A
B
4
1
A. 3
a
B.
a
≤
3
C. 3
a
D.
a
3
11.已知 M 是 ABC△
的外心,
ABC
60
,
AC ,则 ABC△
4
A.
2 3
3
B. 2 3
C.
4 3
3
D.
5 3
3
12.如图,在 Rt ABC△
中, ACB
为90 ,CD AB
,
cos
A.
BCD
9
10
,
2
3
B.
1
BD ,则边 AB 的长是(
9
10
9
5
C.2
D.
)
A
外接圆的半径是(
)
C
D
B
第 II 卷(非选择题 共 84 分)
二、填空题(本大题共 5 个小题,每小题 3 分,共 15 分)请将答案直接写在相应题的横线
上.
13.234610000 用科学记数法表示为
14.观察一组数 2、5、11、23、( )、95、…,括号内的一个数应该是
(保留三个有效数字).
.
15.分解因式 22
x
3
x
1
.
16.如图, AD 是 ABC△
的中线,
ADC
45
,
BC
2cm
,把 ACD△
沿 AD 对折,
使点C 落在 E 的位置,则 BE
cm.
E
D
A
C
B
17.某体育场的环行跑道长 400 米,甲、乙同时从同一起点分别以一定的速度练习长跑和骑
自行车.如果反向而行,那么他们每隔 30 秒相遇一次.如果同向而行,那么每隔 80 秒乙就
追上甲一次.甲、乙的速度分别是多少?设甲的速度是 米/秒,乙的速度是 y 米/秒.则列
出的方程组是
三、解答题(本大题共 8 个小题,共 69 分)要求写出必要的解答过程或演算步骤.
18.(每小题 5 分,共 10 分)
.
(1)计算:
cos60
|1
3 |
(2 tan 30 )
12
5
.
(2)先化简,再求值:
2
a
b
ab
2
a
2
b
ab
2
a
b a
2
ab b
2
(其中 3
a ,
b ).
1
2
19.(本小题 6 分)
解不等式组
1
2
x
1
x
4
2
≤ ,
x
3
,
并将其解集表示在数轴上.
20.(本小题 7 分)
2
x
解方程
x
1
x
0
3
2
.
x
21.(本小题 8 分)
袋中有 2 个红球、1 个白球,它们除颜色外完全相同.
(1)求从袋中任意取出 1 球是红球的概率;
(2)先从袋中任意取出 1 球,然后放回,再从袋中任意取出 1 球,请用画树状图或列表格
法求两次都取到红球的概率.
22.(本小题 8 分)
某班要从甲、乙、丙三名候选人中选出一名参加学校组织的知识竞赛.班上对三名候选人进
行了笔试和口试两次测试,测试成绩如下表:
测试项目
笔试
口试
甲
70
90
测试成绩(分)
乙
80
70
丙
85
65
班上 50 名学生又对这三名候选人进行了民主投票,三人的得票率(没有弃权票,每位学生
只能投三人中的一票)如下图,每得一票记 1 分.
(1)请分别算出三人的得票分;
(2)如果根据三项得分的平均成绩高者被当选,那么谁将被当选(精确到 0.01)?
(3)如果根据笔试、口试、投票三项成绩按 5∶3∶2 的比例确定成绩,根据成绩的加权平
均数高者当选,那么谁又将被当选?
23.(本小题 8 分)
甲 30%
丙 40%
乙 30%
( 0
k )图象经过点 (1 2), ,并与直线 2
y
(
A x
x b
交于点 1
y, ,
)
1
如图,反比例函数
y
k
x
y, ,且满足 1
x
2
)
(
2
(
B x
x
2
)(1
x x
1 2
) 3
.
(1)求 k 的值;
(2)求b 的值及点 A B, 的坐标.
y
O
B
A
x
24.(本小题 10 分)
如图,已知 AB 是 O 的直径,直线CD 与 O 相切于C 点, AC 平分 DAB
(1)求证: AD CD
;
.
(2)若
AD ,
2
AC ,求 O 的半径 R 的长.
6
D
3
4
C
2
1
A
O
B
25.(本小题 12 分)
如图,已知 OAB△
的顶点 (3 0)
A , , (0 1)
B , ,O 是坐标原点.将 OAB△
绕点O 按逆时针旋
ODC△
转 90°得到
(1)写出C D, 两点的坐标;
(2)求过C D A, , 三点的抛物线的解析式,并求此抛物线的顶点 M 的坐标;
(3)在线段 AB 上是否存在点 N 使得 NA NM
请说明理由.
?若存在,请求出点 N 的坐标;若不存在,
M
y
D
B
O
C
x
A
四川省雅安市二○○七年高中阶段教育学校招生考试
数学试题参考答案及评分意见
一、选择题
1~5.BACCB
二、填空题
6~10.DCBAD
11~12.CD
13.
2.35 10
8
14.47
15.(2
x
1)(
x
1)
16. 2
17.
30(
80(
x
y
)
y
)
x
,
400
400
三、解答题
18.(10 分)
(1)解:原式
1
2
( 3 1)
2
3
3
5
2
······················································· 3 分
1
2
4 3
3
3 1 2
3
3
··························································· 4 分
5
2
.················································································· 5 分
(2)解:原式
)
(
a a b
b
(
a b a b
)(
ab
)
b a
(
)
a b
2
············································· 2 分
)
(
a a b
b
(
ab
)(
a b a b
b a
)
a b
(
2
)
············································· 3 分
2
a
a b
1
a b
2 1
a
a b
···················································································4 分
当 3
a ,
b 时,
1
2
2
3
3
原式
2
1
a
a b
19.(6 分)
1 16
1
5
2
.·············································································5 分
解:
2
1
x
1
x
4
2
≤ ,
x
3
···························································································· 1 分
2
3
x
≤
3(
1)
x
≤
4
x
··························································································· 2 分
≤ ,
3
x
2
3
x
··································································································· 3 分
≤ .···························································································· 4 分
3
x
3
2
3
2
1 0
1 3
2
2
20.(7 分)
解:将原方程去分母得
·································································· 6 分
22
x
2(
x
1)(
x
2) 3 (
x x
1)
········································································ 2 分
··························································································· 3 分
x
4 0
23
x
(3
x
4)(
x
1) 0
4
3
x 或
1
x 或
x ·························································································· 5 分
4
3
x ,都是方程的解.····························································· 6 分
经检验
1
所以原方程的解为
x 或
4
3
x .··································································· 7 分
1
21.(8 分)
解:(1)任意取出 1 球的取法有 3 种,其中是红球的取法有 2 种.····························1 分
则任意取出 1 球是红球的概率为
2
3
.···································································3 分
(2)依题意,任意取出 1 球,然后放回,再从中任意取出 1 球的树状图如下:
则两次都取到红球的概率为
4
9
.········································································· 8 分
···························6 分
22.(8 分)
解:(1)三人的得票分分别为
甲:50 30% 15
乙:50 30% 15
丙:50 40% 20
(2)三项得分的平均成绩
分
分
分······················································································ 3 分
70 90 15
3
80 70 15
3
85 65 20
甲:
乙:
丙:
≈
58.33
55.00
≈
56.67
3
由题意得甲将被当选.····················································································· 6 分
(3)由题意三人的平均得分分别为
甲:
乙:
丙:
5 70 3 90 2 15
5 80 3 70 2 15
5 3 2
5 3 2
5 3 2
5 85 3 65 2 20
65
64
66
k
1
(2)由题意
所以丙将被当选.····························································································8 分
23.(8 分)
解:(1)反比例函数
y
( 0
k )图象经过点 (1 2), ,
k
x
.························································································· 2 分
2
k
2
y
y
,
2
x
2
x b
x b
2
2
x
22
x
bx
2 0
①···············································································4 分
x
1
x
2
1
·················································································· 5 分
b
(无“ ”可不扣分)
2 16 0
b
2
)(1
,
x
2
x x
1 2
(1 1) 3
x x
1 2
) 3
x
则由 1
(
b
2
3
b .··································································································· 6 分
①为 22
x
3
x
x
1
2
,
x
2
2 0
1
2
1 1
y
,
y
4
.
即 (2 1)
A , ,
B
1
2
, .··············································································· 8 分
4
24.(10 分)
解:(1)连接OC ,
直线CD 与 O 相切于C 点, AB 是 O 的直径,
又 AC 平分 DAB
OC CD
DAB
,
.
2
.······················································ 1 分
DAB
,··································· 3 分
1
1
2
2 1
又
∥ ,
AD OC
AD CD
COB
D
3
4
C
2
1
A
O
B
.······························································································· 4 分
(2)又连接 BC ,则
在 ADC△
和 ACB△
ACB
90
,
中
2
1
ADC
△
AD AC
R
AC
2
, 3
ACB
∽△
90
,·····································································6 分
ACB
.·····················································································7 分
··································································································9 分