2007 年广西河池市中考数学真题及答案
(考试时间为 120 分钟,满分 120 分)
注意:本试卷分为试题卷和答题卷两部分,请把答案写在答题卷上,在试题卷上答题无效
..........
一、填空题(本大题共 10 小题,每小题 2 分,共 20 分.)
1.如果收入 200 元记作+200 元,那么支出 150 元,记作
元.
2.如图 1,直线 a,b被直线 c所截,且 a
b∥ ,
如果∠1=65°,那么∠2=
.
3.分解因式: 2 1
x
4.不等式 2
1 5
x 的解集是
.
.
c
c
1
2
图 1
图1
a
a
b
b
5.龙滩电站第一期工程年发电量为 157 亿千瓦时,用科学记数法表示 157 亿千瓦时
=
千瓦时.
6.一副三角板,如图 2 叠放在一起,∠的度数是
度.
7 . 已 知 在 Rt ABC△
中 , ∠C 为 直 角 , AC = 4cm , BC = 3cm ,
图 2
sin∠A=
.
8.若⊙O和⊙O 相切,它们的半径分别为 5 和 3,则圆心距 OO 为
.
9.根据图 3 中的程序,当输入 x =3 时,输出的结果 y =
.
输
入
x
y =x+5 (x≤1)
y =-x+5(x>1)
图 3
输
出
y
10.古希腊数学家把 1,3,6,10,15,21,……,叫做三角形数,根据它的规律,则第 100 个三角形数与
第 98 个三角形数的差为
.
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,只有一项是正确的,
每小题选对得 3 分,选错、不选或多选均得零分)
11.下列运算正确的是(
)
A. 5
x
5
x
10
x
B. 5
x x
5
10
x
C. 5 5
)x
(
10
x
D. 20
x
2
x
10
x
12.图 4 中几何体的左视图是(
)
图 4
A.
B.
C.
D.
13.甲、乙两袋均有红、黄色球各一个,分别从两袋中任意取出一球,那么所取出的两球是同色球的概率
)
为(
2
3
A.
B.
1
2
C.
1
3
D.
1
6
14.小明准备用 22 元钱买笔和笔记本,已知每支笔 3 元,每本笔记本 2 元,他买了 3 本笔记本后,其余的
钱用来买笔,那么他最多可以买(
A.3 支笔
C.5 支笔
15.若一个图形绕着一个定点旋转一个角( 0
B.4 支笔
)
D.6 支笔
180
≤
)后能够与原来的图形重合,那么这个图形叫
做旋转对称图形.例如:等边三角形绕着它的中心旋转 120°(如图 5),能够与原来的等边三角形重合,
因而等边三角形是旋转对称图形.显然,中心对称图形都是旋转对称图形,但旋转对称图形不一定是中
心对称图形.下面四个图形中,旋转对称图形个数有(
)
120
图 5
A. 1
B.2
C.3
D. 4
A.
16.已知二次函数
y
4
4
ac
17.已知正比例函数 y
0
b
,
0
b
,
C.
ac
a
a
2
2
ax
2
bx
(
c a
的最大值为 0,则(
0)
)
0
0
B.
D.
a
a
0
b
,
0
b
,
2
2
4
4
ac
ac
0
0
kx ( 0
k )的函数值 y 随 x 的增大而增大,则一次函数 y
kx
的图象大致是
k
(
)
y
y
O
O
x
x
y
O
x
y
O
x
18.如图 6,在矩形 ABCD中,AB=3,AD=4,点 P在 AD上,PE⊥AC于 E,PF⊥BD于 F,则 PE+PF等于(
)
C.
D.
A.
A.
7
5
B.
12
5
C.
B.
13
5
D.
14
5
A
B
P
E
F
图 6
D
C
三、解答题 (本大题共 8 小题,满分 76 分.解答应写出文字说明、证明过程或演算步骤.)
19.(本小题满分 8 分)
计算
1
2
( 1)
2007
1
4
5
20.(本小题满分 9 分)
如图 7,已知网格上最小的正方形的边长为 1.
y
A
(1)分别写出 A、B、C三点的坐标;
(2)作△ABC关于 y轴的对称图形△ A B C
B
C
O
x
(不写作法);
(3)求△ABC的面积.
21. (本小题满分 8 分) .
图 7
如图 8,AD=BC,请添加一个条件,使图中存在全等三角形并给予证明.
你所添加的条件为:
;
得到的一对全等三角形是△______≌△______.
证明:
P
A
C
D
B
图 8
22. (本小题满分 9 分)
三个生产日光灯管的厂家在广告中宣称,他们生产的日光灯管在正常情况下,灯管的使用寿命为 12 个
月.工商部门为了检查他们宣传的真实性,从三个厂家各抽取 11 只日光灯管进行检测,灯管的使用寿命(单
位:月)如下:
甲厂
乙厂
7
7
8
7
9
9
9
9
9
10
11
10
13
12
14
12
16
12
17
13
19
14
丙厂
7
7
8
8
8
12
13
14
15
16
17
试问:(1)这三个厂家的广告,分别利用了统计中的哪一个特征数(平均数、中位数、众数)进行宣传?
(2)如果三种产品的售价一样,作为顾客的你选购哪个厂家的产品?请说明理由.
23.(本小题满分 10 分)
今年“五一”黄金周期间,河池市某旅行社接待一日游和三日游的旅客共 1600 人,收取旅游费 129 万
元,其中一日游每人收费 150 元,三日游每人收费 1200 元. 该旅行社接待的一日游和三日游旅客各多少
人?
24.(本小题满分 10 分)
某早餐店每天的利润 y(元)与售出的早餐 x(份)之间的函数关系如图 9 所示.当每天售出的早餐超
过 150 份时, 需要增加一名工人.
(1)该店每天至少要售出
份早餐才不亏本;
(2)求出150 < x ≤ 300 时,y关于 x的函数解析式;
(3)要使每天有 120 元以上的盈利,至少要售出
多少份早餐?
(4)该店每出售一份早餐,盈利多少元?
(5)除上述信息外,你从图象中还能获取什么信息?
请写出一条信息.
230
180
100
80
O
-50
(元)
y
。
(份)
x
300
50
150
250
图 9
25.(本小题满分 10 分)
如图 10,半圆 O为△ABC的外接半圆,AC为直径,D为 BC 上的一动点.
(1)问添加一个什么条件后,能使得
BD BE
BC BD
?请说明理由;
(2)若 AB∥OD,点 D所在的位置应满足什么条件?请说明理由;
(3)如图 11,在 (1)和(2)的条件下,四边形 AODB是什么特殊的四边形?证明你的结论.
D
B
E
·
O
图 10
A
B
E
D
C
A
O
图 11
C
26. (本小题满分 12 分)
如图 12, 四边形 OABC为直角梯形,A(4,0),B(3,4),C(0,4). 点 M 从O 出发以每秒 2 个单
位长度的速度向 A 运动;点 N 从 B 同时出发,以每秒 1 个单位长度的速度向C 运动.其中一个动点到达终
点时,另一个动点也随之停止运动.过点 N 作 NP 垂直 x 轴于点 P ,连结 AC交 NP于 Q,连结 MQ.
(1)点
(填 M或 N)能到达终点;
(2)求△AQM的面积 S与运动时间 t的函数关系式,并写出自变量 t的取值范围,当 t为何值时,S
的值最大;
(3)是否存在点 M,使得△AQM为直角三角形?若存在,求出点 M的坐标,若不存在,说明理由.
y
C
N
B
Q
O
M
P
图 12
A
x
2007 年中等学校招生河池市统一考试试题
数学(课改区)参考答案及评分标准
一、填空题
1. 150
2. 115°
3. (x+1) (x-1) 4. x>3
5. 1.57×1010
6. 105
7.
3
5
二、选择题
8. 8 和 2
9. 2
10.199
11.B 12.A
13.B
14.C
15.C
16.D
17.A
18.B
三、解答题
19.计算
1
2
( 1)
2007
1
4
5
解: 原式=
1 1+
2
= 1 1 5
= 5
1 5(后面三个数中每计算正确一个得 2 分) ·························6 分
2
·························7 分
·························8 分
20.解: (1) A( 3 ,3),B( 5 ,1),C( 1 ,0)
·························3 分
(2)图略······································································································ 6 分
(3)
S
△
ABC
5
······························································································ 9 分
21.所添加条件为 PA=PB··················································································· 2 分
得到的一对全等三角形是△PAD≌△PBC ····························································· 4 分
证明:∵PA=PB ·······························································································5 分
∴∠A=∠B ··································································································· 6 分
又∵AD=BC ··································································································7 分
∴△PAD≌△PBC ····························································································· 8 分
所添加条件,只要能证明三角形全等,按上面评分标准给分.
22.答:(1)甲厂的广告利用了统计中的平均数.················································· 2 分
····························································· 4 分
乙厂的广告利用了统计中的众数.
····························································· 6 分
丙厂的广告利用了统计中的中位数.
(2) 选用甲厂的产品. 因为它的平均数较真实地反映灯管的使用寿命···················· 9 分
或选用丙厂的产品.因为丙厂有一半以上的灯管使用寿命超过 12 个月······················· 9 分
23. 解:设接待 1 日游旅客 x 人,接待 3 日游旅客 y ,根据题意得·························· 1 分
150
x
x
y
1200
y
1600
1290000
解这个方程组,得
x
y
600
1000
································································ 6 分
································································ 9 分
答:该旅行社接待 1 日游旅客 600 人,接待 3 日游旅客 1000 人.····························10 分
24. 解: (1) 50 ····················································································· 2 分
(2)设函数的解析式为 y =kx+b,由题意得 ························································3 分
70
解方程组得
180
230
k b
k b
1
k
b
························································ 5 分
······································································6 分
250
300
所以函数的解析式为 y =x 70
(3) 解不等式 x 70>120 得 x>190
因此,至少要售出 190 份早餐,才能使每天有 120 元以上的盈利.····························8 分
······················································· 9 分
(4)该店每出售一份早餐,盈利 1 元.
············································································ 10 分
(5)信息合理即可.
25.解: (1)添加 AB=BD ········································································································2 分
∵AB=BD ∴ AB = BD ∴∠BDE =∠BCD················································································ 3 分
又∵∠DBE =∠DBC
∴△BDE∽△BCD
∴
BD BE
BC BD
··································································································································4 分
(2)若 AB∥DO,点 D所在的位置是 BC 的中点 ····················································5 分
∴∠ADO =∠BAD ··································································· 6 分
∵AB∥DO
∵∠ADO =∠OAD ∴∠OAD =∠BAD ∴ DB = DC ·············································· 7 分
(3)在(1)和(2)的条件下,.
∵ AB = BD = DC
∴∠BDA =∠DAC ∴ BD∥OA
又∵AB∥DO
∴四边形 AODB是平行四边形
········································· 9 分
∴平行四边形 AODB是菱形 ··············································· 10 分
∵OA=OD
26. 解:(1)点 M ····················································································· 1 分
(2)经过 t秒时, NB t ,
4 2
t
,
AM
CN
则
3
t
2
OM t
∵ BCA
= MAQ
= 45
∴
QN
CN
3
t
AM PQ
∴
S
△
AMQ
2
t
t
1
2
2
·························································2 分
PQ
∴ 1
t
1 (4 2 )(1
2
t
t
)
······························································································· 3 分
∴
S
2
2
t
t
2
1
2
9
4
··································································· 5 分
∵0
t≤ ≤ ∴当
2
t 时,S的值最大. ························································ 6 分
(3)存在.
····························································································7 分
t
1
2
设经过 t秒时,NB=t,OM=2t
则
CN
,
3
t
AM
4 2
t
∴ BCA
= MAQ
= 45
····································································· 8 分
①若
AQM
90
,则 PQ 是等腰 Rt△ MQA 底边 MA 上的高
∴ PQ 是底边 MA 的中线
∴
PQ AP
1
2
MA
∴
1
1
2
(4 2 )
t
t
1
2
∴
t
∴点 M 的坐标为(1,0)
········································································10 分
②若
QMA
90
,此时QM 与QP 重合
∴QM QP MA
4 2
t
∴1
t
∴ 1t
∴点 M 的坐标为(2,0)
········································································ 12 分