2008 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.
三
四
五
一
二
17-1
20-2
9
2
23
24
25
26
总分 合分人 复分人
题
次
得
分
得 分 评卷人 复评人
一、填空题(本题共 8 个小题,每小题 3 分,满分 24 分)
1、-8 的绝对值是
.
2、函数 y=
2x 中的自变量 x 的取值范围是
.
3、△ABC 中,∠A=55,∠B=25,则∠C=
.
4、方程
2 x
11
的解为 x =
.
5、如 图 , P 为 菱 形 ABCD 的 对 角 线 上 一 点 , PE⊥ AB 于 点 E, PF⊥ AD 于 点 F, PF=3cm, 则 P 点到 AB
的距离是
A
cm.
D
P
B
F
E
C
D
A
B
C
(第 5 题)
(第 6 题)
6、如图,在 Rt△ABC 中,∠C=90,AB=10cm,D 为 AB 的中点,则 CD=
7、已知 a、b为两个连续整数,且 a< 7 <b,则 b
8、在一次捐款活动中,某班 50 名同学人人拿出自己的零花钱,有捐 5 元、10 元、20 元的,还有捐 50 元
cm.
a =
.
和 100 元的。右边的统计图反映了不同捐款数的人数比例,那么该班同学平均每人捐款
元.
100 元
12%
50 元
16%
5 元
8%
10 元
20%
20 元
44%
(第 8 题)
得 分 评卷人 复评人
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项的代号填在下面的表格里:
题 号
答 案
9
10
11
12
13
14
15
16
9、下面计算正确的是(
A、
2 1
2
B、
)
4
2
C、(
3nm
)2=
6nm
10、要反映长沙市一周内每天的最高气温的变化情况,宜采用(
D、
6
mm
)
2
4
m
A、条形统计图 B、扇形统计图 C、折线统计图
D、频数分布直方图
11、若点 P( a , a4 )是第二象限的点,则 a 必须满足(
)
A、 a <4
B、 a >4
C、 a <0
D、0< a <4
12、如图是每个面上都有一个汉字的正方体的一种展开图,那么在正
“迎”相对的面上的汉字是(
)
方 体 的 表 面 , 与
讲
文 明 迎 奥
A、文
B、明
C、奥
D、运
运
13、在同一平面直角坐标系中,函数
y
A、0 个
B、1 个
x
C、2 个
D、3 个
1 与函数 x
y 的图象交点
(第 12 题)
个数是(
)
14、在同一时刻,身高 1.6 米的小强在阳光下的影长为 0.8 米,一棵大树的影长为 4.8 米,则树的高度为
(
)
A、4.8 米
B、6.4 米
C、9.6 米
D、10 米
15、如图,P 为⊙O 外一点,PA 切⊙O 于点 A,且 OP=5,PA=4,则 sin∠APO 等于(
)
4
A、 5
P
3
B、 5
A
·
O
4
C、 3
3
D、 4
.
.
(第 16 题)
16、二次函数
A、 a <0
(第 15 题)
ax
c
2
y
bx
B、 abc >0
的图象如图所示,则下列关系式不正确的是(
)
C、
cba
>0
D、
b
2 >0
4
ac
得 分 评卷人 复评人
三、解答题(本题共 6 个小题,每小题 6 分,满分 36 分)
17、计算:
273
sin2
30
(
1
0)
15
.
18、先化简,再求值:
2
1
a
4
2
2
a
a
1a
,其中 2
.
19、在下面的格点图中,每个小正方形的边长均为 1 个单位,请按下列要求画出图形:
(1)画出图①中阴影部分关于 O 点的中心对称图形;
(2)画出图②中阴影部分向右平移 9 个单位后的图形;
(3)画出图③中阴影部分关于直线 AB 的轴对称图形.
(图①)
(图②)
(图③)
20、解不等式组:
1
01
2
34
14
x
x
x
,并将其解集在数轴上表示出来.
-6
-5
-4
-3
-2
-1
0
1
2
3
21、当 m 为何值时,关于 x 的一元二次方程
x
42
mx
1
2
0
多少?
有两个相等的实数根?此时这两个实数根是
22、某商场开展购物抽奖活动,抽奖箱中有 4 个标号分别为 1、2、3、4 的质地、大小相同的小球,顾客任
意摸取一个小球,然后放回,再摸取一个小球,若两次摸出的数字之和为“8”是一等奖,数字之和为
“6”是二等奖,数字之和为其它数字则是三等奖,请分别求出顾客抽中一、二、三等奖的概率.
得 分 评卷人 复评人
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)
“5·12”汶川大地震后,灾区急需大量帐篷。某服装厂原有 4 条成衣生产线和 5 条童装生产线,工厂
决定转产,计划用 3 天时间赶制 1000 顶帐篷支援灾区。若启用 1 条成衣生产线和 2 条童装生产线,一天可
以生产帐篷 105 顶;若启用 2 条成衣生产线和 3 条童装生产线,一天可以生产帐篷 178 顶.
(1)每条成衣生产线和童装生产线平均每天生产帐篷各多少顶?
(2)工厂满负荷全面转产,是否可以如期完成任务?如果你是厂长,你会怎样体现你的社会责任感?
得 分 评卷人 复评人
24、(本题满分 8 分)
如图,在□ABCD 中,BC=2AB=4,点 E、F 分别是 BC、AD 的中点.
(1)求证:△ABE≌△CDF;
(2)当四边形 AECF 为菱形时,求出该菱形的面积.
A
F
D
B
E
C
得 分 评卷人 复评人
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)
在平面直角坐标系中,一动点 P( x ,y)从 M(1,0)出发,沿由 A(-1,1),B(-1,-1),C(1,-1),
D(1,1)四点组成的正方形边线(如图①)按一定方向运动。图②是 P 点运动的路程 s(个单位)与运动
时间 t (秒)之间的函数图象,图③是 P 点的纵坐标 y与 P 点运动的路程 s之间的函数图象的一部分.
·P
(图①)
(图②)
(1)s与 t 之间的函数关系式是:
(2)与图③相对应的 P 点的运动路径是:
首次到达点 B;
(图③)
;
;P 点出发
秒
(3)写出当 3≤s≤8 时,y与 s之间的函数关系式,并在图③中补全函数图象.
得 分 评卷人 复评人
26、(本题满分 10 分)
如图,六边形 ABCDEF 内接于半径为 r(常数)的⊙O,其中 AD 为直径,且 AB=CD=DE=FA.
(1)当∠BAD=75时,求BC⌒的长;
(2)求证:BC∥AD∥FE;
(3)设 AB= x ,求六边形 ABCDEF 的周长 L 关于 x 的函数关系式,并指出 x 为何值时,L 取得最大值.
B
A
O·
2008 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
F
C
E
D
一、填空题
1、8
5、3
二、选择题
2、x≥2
6、5
3、100
7、5
4、3
8、31.2
题号
答案
9
D
10
C
11
C
12
A
13
A
14
C
15
B
16
C
三、解答题
17.原式=3+2× 2
1 -1·················································································· (3 分)
=3+1-1·························································································(4 分)
=3·······························································································(6 分)
2
=
a
2
a
2
a
1
2
a
2
a
2
a
·····································································(2 分)
18.原式=
a
2
2
a
a
2
2
a
a
1
······························································································ (4 分)
2
a
2 .·········································································(6 分)
1a 时,原式= 5
当 2
········································································ (3 分)
2
=
=
19.图略(“2008”字样),三部分图形各 2 分,共 6 分.
20.由
1
x
2
4 3
1
≤
0
x
14
x
得
x
x
2
5
,······························································ (4 分)
21.由题意,△=(-4)2-4(m- 2
即 16-4m+2=0,m= 2
不等式组的解集为-5<x≤2.································································ (5 分)
解集在数轴上表示略.········································································· (6 分)
1 )=0·································································· (2 分)
9 .················································································ (4 分)
9 时,方程有两个相等的实数根 x1=x2=2.········································· (6 分)
1 ,·····································································(2 分)
3 ,·····································································(4 分)
3 .······································································ (6 分)
22.抽中一等奖的概率为 16
抽中二等奖的概率为 16
抽中三等奖的概率为 4
当 m= 2
105
178
四、解答题
23.(1)设每条成衣生产线和童装生产线平均每天生产帐篷各 x、y 顶,则············ (1 分)
2
y
x
2
3
y
x
解得 x=41,y=32.
答:每条成衣生产线平均每天生产帐篷 41 顶,每条童装生产线平均每天生产帐篷 32 顶.
·············································································································· (5 分)
,······················································································· (3 分)
(2)由 3(4×41+5×32)=972<1000 知,即使工厂满负荷全面转产,还不能如期完成任务.
········································································································(7 分)
可以从加班生产、改进技术等方面进一步挖掘生产潜力,或者动员其它厂家支援等,想法尽早完成生
产任务,为灾区人民多做贡献.··································································· (8 分)
24.(1)证明略;······················································································· (4 分)
(2)当四边形 AECF 为菱形时,△ABE 为等边三角形,······································· (6 分)
四边形 ABCD 的高为 3 ,············································································ (7 分)
∴菱形 AECF 的面积为 2 3 .·······································································(8 分)
五、解答题
25.(1)S= t2
1 (t≥0)·················································································· (2 分)
(2)M→D→A→N,····················································································· (4 分)
10···········································································································(5 分)
(3)当 3≤s<5,即 P 从 A 到 B 时,y=4-s;··················································· (6 分)
当 5≤s<7,即 P 从 B 到 C 时,y=-1;··························································· (7 分)
当 7≤s≤8,即 P 从 C 到 M 时,y=s-8.························································· (8 分)
补全图象略.·························································································· (10 分)
26.(1)连结 OB、OC,由∠BAD=75,OA=OB 知∠AOB=30,································· (1 分)
∵AB=CD,∴∠COD=∠AOB=30,∴∠BOC=120,···············································(2 分)
r2 .····················································································· (3 分)
故BC⌒的长为 3
(2)连结 BD,∵AB=CD,∴∠ADB=∠CBD,∴BC∥AD,···································(5 分)
同理 EF∥AD,从而 BC∥AD∥FE.····························································(6 分)
(3)过点 B 作 BM⊥AD 于 M,由(2)知四边形 ABCD 为等腰梯形,从而 BC=AD-2AM=2r-2AM.
∵AD 为直径,∴∠ABD=90,易得△BAM∽△DAB
AB2
x2 ······································· (8 分)
x
x2
,同理 EF=2r- r
,∴BC=2r- r
= r
∴AM= AD
2
x2
2
4
r
)=
∴L=4x+2(2r- r
,其中 0<x< r2
······· (9 分)
2 2
xr
6
r
2
∴当 x=r 时,L 取得最大值 6r.
x
=
4
r
2
xr
(10 分)
(7 分)