2007 年湖南省长沙市中考数学真题及答案
考生注意:本试卷共 26 道小题,时量 120 分钟,满分 120 分.
一、填空题(本题共 8 个小题,每小题 3 分,满分 24 分)
1.如图,已知直线 a
b∥ , 1 35
∠
,则 2∠ 的度数是
.
2.请写出一对互为相反数的数:
和
.
c
1
2
a
b
cm.
3.计算
x
y
.
y
x
x
10cm
4. ABC△
5.投掷一枚质地均匀的普通骰子,朝上的一面为 6 点的概率是
y
中, D E, 分别是 AB AC, 的中点,当
BC
时, DE
.
6.计算: 18
8
.
7.单独使用正三角形、正方形、正六边形、正八边形四种地砖,不能镶嵌(密铺)地面的是
8.如图,点 A B, 在数轴上对应的实数分别为 m n, ,则 A B, 间的距离是
表示)
.
.(用含 m n, 的式子
A
m
0
B
n
x
二、选择题(本题共 8 个小题,每小题 3 分,满分 24 分)
请将你认为正确的选择支的代号填在下面的表格里:
题号
答案
9
10
11
12
13
14
15
16
9.在平面直角坐标系中,点 (3
4), 所在的象限是(
)
D.第四象限
C.第三象限
B.第二象限
)
A.第一象限
10.下列说法正确的是(
A.有两个角为直角的四边形是矩形
C.等腰梯形的对角线相等
11.某校社会实践小组八位成员上街卖报,一天的卖报数如下表:
E
27
A
卖报数(份) 25
C
29
D
28
B
28
成员
B.矩形的对角线互相垂直
D.对角线互相垂直的四边形是菱形
F
28
G
32
H
25
)
C.27
B.26
D.28
B.三条
则卖报数的众数是(
A.25
12.经过任意三点中的两点共可以画出的直线条数是(
A.一条或三条
13.星期天,小王去朋友家借书,下图是他离家的距离 y (千米)与时间 x (分钟)的函数图象,根据图
象信息,下列说法正确的是(
)
A.小王去时的速度大于回家的速度
B.小王在朋友家停留了 10 分钟
C.小王去时所花的时间少于回家所花的时间
D.小王去时走上坡路,回家时走下坡路
y (千米)
C.两条
D.一条
)
2
0
20 30 40
x (分钟)
14.把抛物线
y
向上平移1个单位,得到的抛物线是(
22
x
)
A.
y
2(
x
1)
2
B.
y
2(
x
1)
2
C.
y
22
x
1
D.
y
22
x
1
15.圆锥侧面展开图可能是下列图中的(
)
A.
B.
C.
D.
16.在密码学中,直接可以看到内容为明码,对明码进行某种处理后得到的内容为密码.有一种密码,将
英文 26 个字母 a b c, , ,…, z (不论大小写)依次对应 1,2,3,…,26 这 26 个自然数(见表格).当
明码对应的序号 x 为奇数时,密码对应的序号
;当明码对应的序号 x 为偶数时,密码对应的序号
1
y
y .
13
x
2
x
2
字母
序号
字母
序号
a
1
n
14
b
2
o
15
c
3
p
16
d
4
q
17
e
5
r
18
f
6
s
19
g
7
t
20
h
8
u
21
i
9
v
22
j
10
w
23
k
11
x
24
l
12
y
25
m
13
z
26
按上述规定,将明码“love”译成密码是(
A.gawq
三、解答题(本题共 6 个小题,每小题 6 分,满分 36 分)
)
D.love
B.shxc
C.sdri
17.计算:
2
( 3)
1
2
1
.
2
18.解分式方程:
2
3x
3
x
.
19.如图是某设计师在方格纸中设计图案的一部分,请你帮他完成余下的工作:
(1)作出关于直线 AB 的轴对称图形;
(2)将你画出的部分连同原图形绕点O 逆时针旋转90 ;
(3)发挥你的想象,给得到的图案适当涂上阴影,让图案变得更加美丽.
A
O
20.为了改进银行的服务质量,随机抽查了 30 名顾客在窗口办理业务所用的时间(单位:分钟).下图是
这次调查得到的统计图.请你根据图中的信息回答下列问题:
(1)办理业务所用的时间为 11 分钟的人数是
(2)补全条形统计图;
(3)这 30 名顾客办理业务所用时间的平均数是
分钟.
;
人数
10
8
6
4
2
8 9 10 11 12 13 时间
21.先化简,再求值:
2 (
a a b
)
(
a b
,其中
2
)
a
2008
,
b
2007
.
22.如图所示,某超市在一楼至二楼之间安装有电梯,天花板与地面平行,请你根据图中数据计算回答:
小敏身高 1.78 米,她乘电梯会有碰头危险吗?姚明身高 2.29 米,他乘电梯会有碰头危险吗?
(可能用到的参考数值:sin 27
0.45
,cos 27
0.89
, tan 27
0.51
)
二楼
A
4m
C
4m
一楼
27°
4m
B
四、解答题(本题共 2 个小题,每小题 8 分,满分 16 分)
23.(本题满分 8 分)
小华准备将平时的零用钱节约一些储存起来,他已存有 62 元,从现在起每个月存 12 元;小华的同学小丽
以前没有存过零用钱,听到小华在存零用钱,表示从现在起每个月存 20 元,争取超过小华.
(1)试写出小华的存款总数 1y 与从现在开始的月数 x 之间的函数关系式以及小丽存款数 2y 与月数 x 之间
的函数关系式;
(2)从第几个月开始小丽的存款数可以超过小华?
24.(本题满分 8 分)
,O 为直角边 BC 上一点,以O 为圆心,OC 为半径的圆恰好与斜边 AB
∠
90
中,
C
如图,Rt ABC△
相切于点 D ,与 BC 交于另一点 E .
(1)求证: AOC
(2)若
AOD
≌△
3
BE ,
△
1
;
BD ,求 O 的半径及图中阴影部分的面积 S .
B
E
O
D
A
C
五、解答题(本题共 2 个小题,每小题 10 分,满分 20 分)
25.(本题满分 10 分)
某班到毕业时共结余经费 1800 元,班委会决定拿出不少于 270 元但不超过 300 元的资金为老师购买纪念品,
其余资金用于在毕业晚会上给 50 位同学每人购买一件文化衫或一本相册作为纪念品.已知每件文化衫比每
本相册贵 9 元,用 200 元恰好可以买到 2 件文化衫和 5 本相册.
(1)求每件文化衫和每本相册的价格分别为多少元?
(2)有几购买文化衫和相册的方案?哪种方案用于购买老师纪念品的资金更充足?
26.(本题满分 10 分)
3
4
∠
中,
BAD
BC ,
AB ,
如图, ABCD
于 F , FE , DC 的延长线交于点G ,设 BE x , DEF△
(1)求证: BEF
(2)求用 x 表示 S 的函数表达式,并写出 x 的取值范围;
(3)当 E 运动到何处时, S 有最大值,最大值为多少?
CEG
∽△
120
△
;
的面积为 S .
,E 为 BC 上一动点(不与 B 重合),作 EF
AB
D
A
E
F
B
C
G
2007 年长沙市初中毕业学业考试试卷
数学参考答案及评分标准
2.1, 1 (答案不唯一)
3.1
4.5
6. 2
7.正八边形
8. n m
一、填空题
1.35
1
6
5.
二、选择题
题号
答案
9
D
三、解答题
10
C
11
D
12
A
13
B
14
C
15
D
16
B
9
1
2
1
2
17.原式
························································································3 分
9 ·································································································· 6 分
············································································ 2 分
3(
x
3)
x
18.去分母,得 2
x ·········································································· 5 分
x 是原方程的根.·········································································· 6 分
去括号,移项,合并,得 9
检验,得 9
19.图略.三步各计 2 分,共 6 分.
20.(1)5;··································································································· 2 分
(2)图略;··································································································· 4 分
(3)10.······································································································ 6 分
21.原式
2
2
a
2
ab
2
(
a
2
ab b
2
)
······························································· 2 分
2
2
a
2
ab a
2
2
ab b
2
··································································3 分
2
a
2
b
···························································································4 分
当
a
2008
,
b
2007
时,
原式
( 2008)
2
( 2007)
2
2008 2007 1
··················································· 6 分
22.作CD AC
在 Rt ACD△
∠
交 AB 于 D ,则
tan
CD AC
∠
CAB
CAB
4 0.51 2.04
中,
······························································3 分
(米)····················································· 4 分
所以小敏不会有碰头危险,姚明则会有碰头危险.················································· 6 分
四、解答题
27
,·················································1 分
x
x
20
62 12
····································································· 4 分
y
23.(1) 1
(2)由 20
x
,································································· 7 分
所以从第 8 个月开始小丽的存款数可以超过小华.················································· 8 分
24.(1) AB 切 O 于 D , OD AB
···························································1 分
y
, 2
得 7.75
x
62 12
x
在 Rt AOC△
和 Rt AOD△
中,
OC OD
AO AO
,
························································ 3 分
△
Rt
AOC
≌ △
Rt
AOD
(HL)
········································································ 4 分
(2)设半径为 r ,在 Rt ODB△
中, 2
r
2
3
(
r
2
1)
,解得 4
r ·························· 6 分
由(1)有 AC AD
1
2
AC BC
1
2
S
AC
1
2
AC
1
2
,
2
2
9
(
2
,解得
3)
AC
12
······························ 7 分
2
r
12 9
2
4
54 8
.···································· 8 分
五、解答题
25.(1)设文化衫和相册的价格分别为 x 元和 y 元,则··········································· 1 分
······························································································ 3 分
x
2
y
5
y
x
9
200
解得
x
y
35
26
答:文化衫和相册的价格分别为 35 元和 26 元.···················································· 5 分
(2)设购买文化衫t 件,则购买相册 (50
)t 本,则
1500
≤
35
t
26(50
t
)
≤
1530
········································································ 7 分
200
9
230
9
23
解得
t , 24 , 25 ,即有三种方案.············································ 8 分
t≤ ≤
t 为正整数,
第一种方案:购文化衫 23 件,相册 27 本,此时余下资金 293 元;
第二种方案:购文化衫 24 件,相册 26 本,此时余下资金 284 元;
第三种方案:购文化衫 25 件,相册 25 本,此时余下资金 275 元;····························9 分
所以第一种方案用于购买教师纪念品的资金更充足.············································ 10 分
26.(1)证明略;····························································································3 分
(2)由(1) DG 为 DEF△
中 EF 边上的高,
在 Rt BFE△
中,
∠
B
60
,
EF BE
sin
B
3
2
x
,········································ 4 分
在 Rt CEG△
中,
CE
,
3
x
CG
(3
x
)cos60
x
3
2
,
DG DC CG
,··········································································· 5 分
x
11
2
3
8
S
其中 0
11 3
EF DG
1
2
x ≤ .····························································································· 7 分
,······························································ 6 分
8
3
x
x
2
(3)
a
3
8
0
,对称轴
x ,当 0
11
2
x ≤ 时, S 随 x 的增大而增大,
3
当 3
3 3
S
x ,即 E 与C 重合时, S 有最大值.······················································· 9 分
.······························································································· 10 分
最大