数学试卷
*考试时间120分钟 试卷满分150分
一、选择题(下列各题的备选答案中,只有一个答案是正确的,将正确答案的序号填在题后的括号内,每小题3分,共24分)
1.沈阳市计划从2008年到2012年新增林地面积253万亩,253万亩用科学记数法表示正确的是( ) A.25.310亩
5B.2.5310亩
6C.25310亩
4D.2.5310亩
72.如图所示的几何体的左视图是( )
正面
第2题图
A. B. C. D.
3.下列各点中,在反比例函数y2图象上的是( ) x1) A.(2,
B.,3
231) C.(2,,2) D.(14.下列事件中必然发生的是( )
A.抛两枚均匀的硬币,硬币落地后,都是正面朝上 B.掷一枚质地均匀的骰子,朝上一面的点数是3 C.通常情况下,抛出的篮球会下落 D.阴天就一定会下雨
5.一次函数ykxb的图象如图所示,当y0时,x的取 值范围是( ) A.x0 B.x0
y 3 O x
2
C.x2
D.x2
第5题图
6.若等腰三角形中有一个角等于50,则这个等腰三角形的顶角的度数为( ) A.50
B.80
2C.65或50
D.50或80
7.二次函数y2(x1)3的图象的顶点坐标是( )
A
D
F E
C
第8题图
,3) A.(1
,3) B.(1
,3) C.(1,3) D.(18.如图所示,正方形ABCD中,点E是CD边上一点,连接AE, 交对角线BD于点F,连接CF,则图中全等三角形共有( )
B 2008年沈阳市中等学校招生统一考试 1/12
A.1对 B.2对 C.3对 二、填空题(每小题3分,共24分)
D.4对
9.已知A与B互余,若A70,则B的度数为 . 10.分解因式:2m8m .
11.已知△ABC中,A60,ABC,ACB的平分线交于点O,
3A D
O 则BOC的度数为 .
C 12.如图所示,菱形ABCD中,对角线AC,BD相交于点O,若再补 B 第12题图 充一个条件能使菱形ABCD成为正方形,则这个条件是 (只
填一个条件即可). C B 13.不等式2xx6的解集为 .
14.如图所示,某河堤的横断面是梯形ABCD,BC∥AD,迎水坡
A E 12AB长13米,且tanBAE,则河堤的高BE为 米.
第14题图 515.观察下列图形的构成规律,根据此规律,第8个图形中有 个圆.
D
„„
第1个 第2个 第3个 第15题图
第4个
,,点B的坐标为(111),,点C到直线AB的16.在平面直角坐标系中,点A的坐标为(11)距离为4,且△ABC是直角三角形,则满足条件的点C有 个.
三、(第17小题6分,第18,19小题各8分,第20小题10分,共32分)
117.计算:(1)052723.
2
18.解分式方程:
11x2. x33x
19.先化简,再求值:
1y(xy)(xy)2x22y2,其中x,y3.
3
2008年沈阳市中等学校招生统一考试 2/12
20.如图所示,在66的方格纸中,每个小方格都是边长为1的正方形,我们称每个小正方形的顶点为格点,以格点为顶点的图形称为格点图形,如图①中的三角形是格点三角形. (1)请你在图①中画一条直线将格点三角形分割成两部分,将这两部分重新拼成两个不同的格点四边形,并将这两个格点四边形分别画在图②,图③中; (2)直接写出这两个格点四边形的周长.
图① 图② 图③
第20题图
四、(每小题10分,共20分)
21.如图所示,AB是O的一条弦,ODAB,垂足为C,交O于点D,点E在O上.
(1)若AOD52,求DEB的度数;
E O (2)若OC3,OA5,求AB的长.
B A C D 第21题图
22.小刚和小明两位同学玩一种游戏.游戏规则为:两人各执“象、虎、鼠”三张牌,同时各出一张牌定胜负,其中象胜虎、虎胜鼠、鼠胜象,若两人所出牌相同,则为平局.例如,小刚出象牌,小明出虎牌,则小刚胜;又如,两人同时出象牌,则两人平局. (1)一次出牌小刚出“象”牌的概率是多少?
(2)如果用A,B,C分别表示小刚的象、虎、鼠三张牌,用A1,B1,C1分别表示小明的象、虎、鼠三张牌,那么一次出牌小刚胜小明的概率是多少?用列表法或画树状图(树形图)法加以说明.
小刚 小明
A B C A1 B1 C1
第22题图
2008年沈阳市中等学校招生统一考试 3/12
五、(本题12分)
23.在学校组织的“喜迎奥运,知荣明耻,文明出行”的知识竞赛中,每班参加比赛的人数相同,成绩分为A,B,C,D四个等级,其中相应等级的得分依次记为100分,90分,80分,70分,学校将某年级的一班和二班的成绩整理并绘制成如下的统计图:
一班竞赛成绩统计图 二班竞赛成绩统计图 人数 12 D级 12 16% 10 A级 8 6 C级 44% 5 6 36% 4 2 2 0 A B C D B级4% 等级
第23题图 请你根据以上提供的信息解答下列问题:
(1)此次竞赛中二班成绩在C级以上(包括C级)的人数为 ; (2)请你将表格补充完整:
一班 二班 平均数(分) 中位数(分) 众数(分) 87.6 87.6 90 100 (3)请从下列不同角度对这次竞赛成绩的结果进行分析:
①从平均数和中位数的角度来比较一班和二班的成绩; ②从平均数和众数的角度来比较一班和二班的成绩;
③从B级以上(包括B级)的人数的角度来比较一班和二班的成绩. 六、(本题12分)
24.一辆经营长途运输的货车在高速公路的A处加满油后,以每小时80千米的速度匀速行驶,前往与A处相距636千米的B地,下表记录的是货车一次加满油后油箱内余油量y(升)与行驶时间x(时)之间的关系: 行驶时间x(时) 余油量y(升) 0 100 1 80 2 60 2.5 50 (1)请你认真分析上表中所给的数据,用你学过的一次函数、反比例函数和二次函数中的一种来表示y与x之间的变化规律,说明选择这种函数的理由,并求出它的函数表达式;(不要求写出自变量的取值范围)
(2)按照(1)中的变化规律,货车从A处出发行驶4.2小时到达C处,求此时油箱内余油多少升?
(3)在(2)的前提下,C处前方18千米的D处有一加油站,根据实际经验此货车在行驶中油箱内至少保证有10升油,如果货车的速度和每小时的耗油量不变,那么在D处至少加多少升油,才能使货车到达B地.(货车在D处加油过程中的时间和路程忽略不计)
2008年沈阳市中等学校招生统一考试 4/12
七、(本题12分)
BACDAE,25.已知:如图①所示,在△ABC和△ADE中,ABAC,ADAE,
且点B,A,D在一条直线上,连接BE,CD,M,N分别为BE,CD的中点. (1)求证:①BECD;②△AMN是等腰三角形.
(2)在图①的基础上,将△ADE绕点A按顺时针方向旋转180,其他条件不变,得到图②所示的图形.请直接写出(1)中的两个结论是否仍然成立;
△PBD∽△AMN.(3)在(2)的条件下,请你在图②中延长ED交线段BC于点P.求证:
C
C N
N E D A B M M D B A E
图② 图①
第25题图 八、(本题14分) 26.如图所示,在平面直角坐标系中,矩形ABOC的边BO在x轴的负半轴上,边OC在y轴的正半轴上,且AB1,OB3,矩形ABOC绕点O按顺时针方向旋转60后得到
矩形EFOD.点A的对应点为点E,点B的对应点为点F,点C的对应点为点D,抛物线yaxbxc过点A,E,D. (1)判断点E是否在y轴上,并说明理由; (2)求抛物线的函数表达式;
(3)在x轴的上方是否存在点P,点Q,使以点O,B,P,Q为顶点的平行四边形的面积是矩形ABOC面积的2倍,且点P在抛物线上,若存在,请求出点P,点Q的坐标;若不存在,请说明理由.
y E A B F C O 第26题图
D x
2
2008年沈阳市中等学校招生统一考试 5/12
2008年沈阳市中等学校招生统一考试
数学试题参考答案及评分标准
一、选择题(每小题3分,共24分) 1.B 2.A 3.D 4.C 5.C 二、填空题(每小题3分,共24分) 9.20
6.D
7.A 8.C
10.2m(m2)(m2)
11.120
13.x4
14.12
12.BAD90(或ADAB,ACBD等)
15.65 16.8 三、(第17小题6分,第18,19小题各8分,第20小题10分,共32分)
17.解:原式1(2)27523 ············································································ 4分 ········································································································ 5分 1233523 ·
································································································································ 6分 36 ·
18.解:12(x3)x ······································································································· 2分
12x6x x7 ······································································································································· 5分
1检验:将x7代入原方程,左边右边 ······································································· 7分
4所以x7是原方程的根 ········································································································ 8分 (将x7代入最简公分母检验同样给分)
19.解:原式xyyx2xyyx2y····························································· 4分
22222xy ····································································································································· 6分
1当x,y3时,
3原式31 ············································································································· 8分 20.解:(1)答案不唯一,如分割线为三角形的三条中位线中任意一条所在的直线等.
·········································· 2分
拼接的图形不唯一,例如下面给出的三种情况:
图① 图② 图③ 图④
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13
图⑤ 图⑥ 图⑦
图⑧ 图⑨
图①~图④,图⑤~图⑦,图⑧~图⑨,画出其中一组图中的两个图形. ···························· 6分 (2)对应(1)中所给图①~图④的周长分别为425,8,425,425; 图⑤~图⑦的周长分别为10,825,825;
图⑧~图⑨的周长分别为245,445.结果正确. ·············································· 10分 四、(每小题10分,共20分)
·21.解:(1)ODAB,·········································································· 3分 ADDB11AOD5226 ·················································································· 5分 22(2)ODAB,ACBC,△AOC为直角三角形, OC3,OA5, DEB由勾股定理可得ACOA2OC252324··························································· 8分
AB2AC8 ················································································································· 10分
122.解:(1)P(一次出牌小刚出“象”牌) ································································· 4分
3(2)树状图(树形图):
2008年沈阳市中等学校招生统一考试 7/12
小刚
A
小明
A1
B1 C1 A1
开始 B B1 C1 A1
C B1 C1
··································································································· 8分
或列表
小刚 小明 A1 (A,A1) (B,A1) (C,A1) B1 (A,B1) (B,B1) (C,B1) C1 (A,C1) (B,C1) (C,C1) A B C ············································································ 8分
由树状图(树形图)或列表可知,可能出现的结果有9种,而且每种结果出现的可能性相同,其中小刚胜小明的结果有3种. ···························································································· 9分
P(一次出牌小刚胜小明)1. ························································································ 10分 3五、(本题12分) 23.解:(1)21 ······················································································································ 2分 (2)一班众数为90,二班中位数为80 ················································································ 6分 (3)①从平均数的角度看两班成绩一样,从中位数的角度看一班比二班的成绩好,所以一班成绩好; ······························································································································ 8分 ②从平均数的角度看两班成绩一样,从众数的角度看二班比一班的成绩好,所以二班成绩好; ··············································································································································· 10分 ③从B级以上(包括B级)的人数的角度看,一班人数是18人,二班人数是12人,所以一班成绩好. ························································································································ 12分 六、(本题12分) 24.解:(1)设y与x之间的关系为一次函数,其函数表达式为ykxb ···················· 1分
100),(180),代入上式得, 将(0,b100k20 解得 kb80b1002008年沈阳市中等学校招生统一考试 8/12
y20x100 ·················································································································· 4分
验证:当x2时,y20210060,符合一次函数; 当x2.5时,y202.510050,也符合一次函数.
可用一次函数y20x100表示其变化规律,
而不用反比例函数、二次函数表示其变化规律. ································································· 5分
y与x之间的关系是一次函数,其函数表达式为y20x100 ··································· 6分
(2)当x4.2时,由y20x100可得y16
即货车行驶到C处时油箱内余油16升. ·············································································· 8分 (3)方法不唯一,如:
方法一:由(1)得,货车行驶中每小时耗油20升, ························································· 9分 设在D处至少加油a升,货车才能到达B地.
636804.22010a16, ································································· 11分
80解得,a69(升) ············································································································ 12分
依题意得,
方法二:由(1)得,货车行驶中每小时耗油20升, ························································· 9分 汽车行驶18千米的耗油量:
18204.5(升) 80D,B之间路程为:636804.218282(千米)
2822070.5(升) ······································································································· 11分 80汽车行驶282千米的耗油量:
70.510(164.5)69(升) ······················································································· 12分
方法三:由(1)得,货车行驶中每小时耗油20升, ························································· 9分 设在D处加油a升,货车才能到达B地.
636804.22010≤a16,
80解得,a≥69 ······················································································································ 11分
······························································ 12分 在D处至少加油69升,货车才能到达B地. ·
依题意得,
七、(本题12分)
25.证明:(1)①BACDAE BAECAD
ABAC,ADAE △ABE≌△ACD BECD ···························································································································· 3分 ②由△ABE≌△ACD得ABEACD,BECD M,N分别是BE,CD的中点,BMCN ······························································ 4分 又ABAC
2008年沈阳市中等学校招生统一考试 9/12
△ABM≌△ACN
AMAN,即△AMN为等腰三角形 ············································································ 6分
(2)(1)中的两个结论仍然成立. ······················································································ 8分 (3)在图②中正确画出线段PD
由(1)同理可证△ABM≌△ACN CANBAM BACMAN 又BACDAE
MANDAEBAC
△AMN,△ADE和△ABC都是顶角相等的等腰三角形 ··········································· 10分 PBDAMN,PDBADEANM △PBD∽△AMN ··········································································································· 12分 八、(本题14分) 26.解:(1)点E在y轴上 ··································································································· 1分 理由如下:
连接AO,如图所示,在Rt△ABO中,AB1,BO3,AO2
sinAOB1,AOB30 2由题意可知:AOE60
BOEAOBAOE306090
·················································································· 3分 点B在x轴上,点E在y轴上. ·(2)过点D作DMx轴于点M
OD1,DOM30
在Rt△DOM中,DM点D在第一象限, 点D的坐标为13,OM 2231 ····································································································· 5分 2,2由(1)知EOAO2,点E在y轴的正半轴上
2) 点E的坐标为(0,······································································································ 6分 点A的坐标为(31), ·
抛物线yax2bxc经过点E,
2008年沈阳市中等学校招生统一考试 10/12
c2
由题意,将A(31),,D31,代入yax2bx2中得 2283a3b21a9 解得 331b2ab534229853······························································· 9分 x2 ·所求抛物线表达式为:yx299(3)存在符合条件的点P,点Q. ··················································································· 10分 理由如下:矩形ABOC的面积ABBO3 以O,B,P,Q为顶点的平行四边形面积为23.
由题意可知OB为此平行四边形一边, 又OB3
OB边上的高为2 ··············································································································· 11分
2) 依题意设点P的坐标为(m,853x2上 点P在抛物线yx299853m2m22
99解得,m10,m253 853P2,P(0,2)218, 以O,B,P,Q为顶点的四边形是平行四边形,
PQ∥OB,PQOB3, 2)时, 当点P1的坐标为(0,点Q的坐标分别为Q1(3,2),Q2(3,2);
A B 2008年沈阳市中等学校招生统一考试 11/12
y E F C D O M x 当点P2的坐标为5328,时,
13333,22点Q的坐标分别为Q3······················································ 14分
,Q4,. ·88(以上答案仅供参考,如有其它做法,可参照给分)
2008年沈阳市中等学校招生统一考试
12/12
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