2009 年湖南省湘潭市中考数学真题及答案
考试时量:120 分钟
满分:120 分
新爱的同学,你好!今天是展示你的才能的时候了,请你仔细审题,认真答题,发挥自己的正常水平,
轻松一点,相信自己的实力!
考生注意:本试卷分试题卷和答题卡两部分,全卷共三道大题,26 道小题;请考生将解答过程全部填
(涂)或写在答题卡上,写在试题卷上无效,考试结束后,将试题卷和答题卡一并上交.
一、选择题(本题共 8 个小题,每小题有且只有一个正确答案,请将正确答案的选项代号涂在答题卡相应
的位置上,每小题 3 分,满分 24 分)
1.下列判断中,你认为正确的是(
)
A.0 的倒数是 0
B. 5 大于 2
D. 9 的值是 3
C. π 是有理数
2.一个正多边形的每个外角都是36°,这个正多边形是(
A.正六边形
B.正八边形
C.正十边形
)
D.正十二边形
)
B.
)
A
O
x
x
3
D.
x ≤
3
3.函数
x ≥
3
x ≥
50
D.100°
0
C.
A °,
中,自变量 x 的取值范围是(
y
A. 3
4.如图,点 A B C, , 在 O 上,
则 BOC
的度数为(
A.130° B.50°
C.65°
5.在 Rt ABC△
A.60°
6.同一时刻,身高 2.26m 的姚明在阳光下影长为 1.13m;小林浩在阳光下的影长为 0.64m,则小林浩的身
高为(
A.1.28m
7.对于样本数据 1,2,3,2,2,以下判断:①平均数为 5;②中位数为 2;③众数为 2;④极差为 2.正
确的有(
A.1 个
90
C °,若
C.30°
A ,则 A 的度数是(
)
B.2 个
(第 4 题图)
B. 45°
D.无法确定
D.0.32m
B.1.13m
C.0.64m
C.3 个
D.4 个
sin
中,
1
2
B
)
)
C
8.在同一直角坐标系中,二次函数
y
2
x
y
与一次函数 2
x 的图象大致是(
2
y
)
y
y
y
2
x
o
o
x
2
o
x
二、填空题(本题共 8 个小题,请将答案写在答题卡相应的位置上,每小题 3 分,满分 24 分)
9. 6.18
10.已知 y 是 x 的反比例函数,当 4
2
B
x 时, 2
y .则 y 与 x 的函数关系式是
的绝对值是
A
.
.
C
x
o
2
D
,
中, AB AC
.
11. ABC△
则 B 的度数是
12.如图,天平盘中每个小球的重量用 x 克表示,
砝码每个 5 克,那么 x
A °,
克.
36
13.已知
m n ,
5
mn ,则 2
m n mn
3
2
.
中, D E F, , 分别是 AB BC AC
14.在等边三角形、正方形、矩形、菱形中,是轴对称图形但不是中心对称图形的是
15.如图, ABC△
已知 DF
使 ADF
16.调查某小区内 30 户居民月人均收入情况,制成如下的频数分
布直方图,收入在 1200~1240 元的频数是
AB∥ ,请补充一个条件:
.
BC∥ , EF
FEC
, , 上的点,
≌△
△
.
,
A
D
.
F
(户)
B
E
(第 15 题图)
C
15
10
5
0
7
3
4
1
1
1120 1160 1200
1240
1280
1320
1360
元
(第 16 题图)
三、解答题(本大题共 10 个小题,解答应写出文字说明、证明过程或演算步骤,请将解答过程写在答题卡
相应的位置上,满分 72 分)
17.(本题满分 6 分)
计算:
4 2 tan 45
°
(π
0
6)
.
18.(本题满分 6 分)
先化简,再求值:
(2
x
2
y
)
(2
x
y
)(2
x
y
) 4
xy
;其中 2009
x
,
y .
1
19.(本题满分 6 分)
某物体的三视图如右图:
(1)此物体是
(2)求此物体的全面积.
体;
20
20
40
40
20
主视图
左视图
俯视图
20.(本题满分 6 分)
解不等式组,并将解集在数轴上表示出来.
x
x
5 3
4
6
x
3
①
②
21.(本题满分 6 分)
如图, B C E, , 是同一直线上的三个点,四边形 ABCD 与四边形CEFG 都是正方形,连结 BG DE, .
(1)观察图形,猜想 BG 与 DE 之间的大小关系,并证明你的结论;
(2)若延长 BG 交 DE 于点 H ,求证: BH DE
.
A
D
G
H
B
C
F
E
22.(本题满分 6 分)
解方程:
40
x
40
2
x
1
.
23.(本题满分 8 分)
小明练习 100 米短跑,训练时间与 100 米短跑成绩记录如下:
时间(月)
1
2
3
成绩(秒)
15.6
15.4
15.2
4
15
(1)请你为小明的 100 米短跑成绩 y (秒)与训练时间 x (月)的关系建立函数模型;
(2)用所求出的函数解析式预测小明训练 6 个月的 100 米短跑成绩;
(3)能用所求出的函数解析式预测小明训练 3 年的 100 米短跑成绩吗?为什么?
24.(本题满分 8 分)
小亮看到路边上有人设摊玩“有奖掷币”游戏,规则是:交 2 元钱可以玩一次掷硬币游戏,每次同时掷两
枚硬币,如果出现两枚硬币正面朝上,奖金 5 元;如果是其它情况,则没有奖金(每枚硬币落地只有正面
朝上和反面朝上两种情况).小亮拿不定主意究竟是玩还是不玩,请同学们帮帮忙!
(1)求出中奖的概率;
(2)如果有 100 人,每人玩一次这种游戏,大约有
人中奖,奖金共约是
元,设摊者约获利
元;
(3)通过以上“有奖”游戏,你从中可得到什么启示?
25.(本题满分 10 分)
如图, AB 是 O 的直径,CD 是弦,CD AB
(1)求证: ACE
CBE
∽△
△
;
于点 E ,
(2)若
AB ,设OE x ( 0
8
x ), 2CE
4
y ,请求出 y 关于 x 的函数解析式;
(3)探究:当 x 为何值时,
tan
D
3
3
.
A
EO
C
D
B
26.(本题满分 10 分)
如图,在平面直角坐标系中,四边形OABC 为矩形,
OP 绕点 P 逆时针方向旋转90°交直线 BC 于点Q ;
OA ,
3
OC , P 为直线 AB 上一动点,将直线
4
(1)当点 P 在线段 AB 上运动(不与 A B, 重合)时,求证:OA BQ AP BP
;
(2)在(1)成立的条件下,设点 P 的横坐标为 m ,线段CQ 的长度为l ,求出l 关于 m 的函数解析式,并
判断l 是否存在最小值,若存在,请求出最小值;若不存在,请说明理由;
(3)直线 AB 上是否存在点 P ,使 POQ△
为等腰三角形,若存在,请求出点 P 的坐标;若不存在,请说
明理由.
y
A
P
B
Q
湘潭市 2009 年初中毕业学业考试
数学试卷参考答案及评分标准
O
C
x
一、选择题(本题共 8 个小题,每小题 3 分,满分 24 分)
1.B
二、填空题(本题共 8 个小题,每小题 3 分,满分 24 分)
5.C
7.D
6.A
2.C
3.B
4.D
8.C
9.6.18
10.
y
11. 72° 12.10
13.15
14.等边三角线
8
x
或 AD FE 或 F 为 AC 中点或 DF 为中位线或 EF 为中位线或 DE
AC∥ 等
或 DF EC
15. AF FC
16.14
三、解答题(本大题共 10 个小题,满分 72 分)
17.(本题满分 6 分)
解:
4 2 tan 45
°
(π
0
6)
2 2 1 1
2 2 1
··································································································4 分
····································································································· 5 分
1 ··············································································································· 6 分
18.(本题满分 6 分)
解:
(2
x
2
y
)
(2
x
y
)(2
x
y
) 4
xy
2
4
x
4
xy
2
y
2
(4
x
2
y
) 4
xy
··································································· 3 分
2
4
x
4
xy
2
y
2
4
x
2
y
4
xy
22y
··········································································································· 4 分
当 2009
x
,
y 时,
1
原式
22
y
··················································································· 6 分
2 1 2
19.(本题满分 6 分)
(1)圆柱······································································································ 2 分
(2)
20π 40 2 π 10
2
··············································································· 4 分
1000π
20.(本题满分 6 分)
······································································································· 6 分
2
3x
·····················································································1 分
x ···············································································2 分
解:不等式①的解集
不等式②的解集 3x ·······················································································4 分
不等式组的解集 2
················································································ 5 分
在数轴上表示(略)·························································································6 分
21.(本题满分 6 分)
(1)猜想: BG DE
BC DC
CG CE
BCG
≌△
(2)在 BCG△
由(1)得 CBG
DGH
中
·············································································· 4 分
··························································································· 5 分
(SAS)············································································ 3 分
DCE
与 DHG△
CDE
°
°
90
BCG
DCE
CGB
DHB
BCG
90
△
BH DE
22.(本题满分 6 分)
·································································································· 6 分
解:方程两边同乘以 (
x x ,得·······································································1 分
2)
40(
x
2) 40
x
(
x x
2)
················································································2 分
2
x
80 0
整理得 2
x
···················································································· 3 分
10
x 或 8x ···························································································5 分
x , 8x 都是原方程的根.···························································· 6 分
经检验
23.(本题满分 8 分)
10
(1)设 y
kx b
依题意得···············································································1 分
15.6
15.4
k b
2
k b
······························································································· 2 分
解答
······························································································· 3 分
的概率是
;································································································· 3 分
(2)25,125,75····························································································6 分
(3)略(只要有理就行)················································································· 8 分
25.(本题满分 10 分)
(1)证明: AB 为 O 直径,
又CD AB
A
△
(2)
A
, Rt
△
CBE
∽△
························································ 3 分
90
°
Rt
∽ △
,
ECB
ACE
AO OE OB OE
ACE
ACE
°即
AE BE
°
90
即 2
CE
CBE
ACE
BCE
ACB
(
90
)(
)
)(4
x
) 16
x
2
············································································ 6 分
AE CE
CE
EB
x
y
(4
(3)解法一:
tan
D
3
3
即
tan
A
3
3
0.2
k
15.8
b
0.2
x
1
4
y
15.8
·························································································· 4 分
(2)当 6
x 时,
y
0.2 6 15.8
································································· 5 分
14.6
·········································································································· 6 分
(3)不能······································································································ 7 分
略(理由合理)·······························································································8 分
24.(本题满分 8 分)
(1)解:掷两枚硬币出现的情况是(正,正)、(正,反)、(反,正)、(反,反),故出现两枚硬币都朝上
CE
AE
3
3
则
2
2
CE
AE
即
1
3
16
(4
2
x
)
x
2
1
3
解得 2
x 或
x (舍去)
4
故当 2
x 时,
tan
D
3
3
···········································································10 分
解法二:
tan
D
3
3
BE
BE
DE CE
4
x
16
x
2
即
3
3
4
x
16
x
2
1
3
(4
16
2
)
x
2
x
解得 2
x 或 4
x (舍去)
故当 2
x 时,
tan
D
26.(本题满分 10 分)
3
3
···········································································10 分
(1)证明: PO PQ
,
APO
BPQ
°,
90
APO
AOP
°,
90
在 Rt AOP△
BPQ
中,
AOP
△
AOP
∽△
BPQ
,则
(2) OA BP AP BP
AP BQ
OA
BP
BQ
,即
即OA BQ AP BP
m
m
)
(4
3
······································· 3 分
3
l
4
m m
3
2
1
3
2
(
m
4
m
4)
5
3
1
3
(
m
2)
2
5
3
5
3
当
2m 时, l 有最小值
(3)解法一
△
POQ
是等腰三角形
.·········································································· 6 分
①若 P 在线段 AB 上,
OPQ
°
90
PO PQ
,又 AOP
△
∽△
BPQ
,
△
AOP
≌△
BPQ
PB AO
,即3 4 m
,
1m ,即 P 点坐标 (1 3), ········································ 8 分
②若 P 在线段 AB 的延长线上, PQ 交CB 的延长线于Q , PO PQ
,
又
△
AOP
∽△
BPQ
,
△
AOP
≌△
BPQ
,
AO PB
,即3
4m
,即 P 点的坐标 (7 3), ,
P
故存在 1
(1 3)
P,, , 使 POQ△
(7 3)
2
为等腰三角形.··············································· 10 分
解法二 POQ△
是等腰三角形
PO PQ
,
即 2
PA
2
AO
2
PB
2
BQ
·············································································· 7 分
则
2
m
2
3
(4
2
m
)
4
m m
3
2
2
··································································· 8 分
整理得 4
m
3
8
m
16
m
2
72
m
63 0
4
m
3
8
m
2
7
m
2
9
m
72
m
63 0
2
m m
(
2
8
m
7) 9(
m
2
8
m
7) 0
(
m
1)(
m
7)(
m
2
9) 0
1 1m , 2
7m , 2
m (舍去)
9
y
A
O
P
B
Q
C
x
故存在 1(1 3)
P , , 2(7 3)
P , 使 POQ△
为等腰三角形.··············································10 分
注:以上各题的其它解法,请参照此标准记分.