2009年辽宁省抚顺市中考数学试题及答案(word版)

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2009年抚顺市初中毕业生学业考试数 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,只有一个是正确的.请将正确答案的选项填写在下表中相应题号下的空格内.每小题3分,共24分) 1.2-的相反数是( ) A .2 B .12-C .2-D .122.某市在一次扶贫助残活动中,共捐款2580000元.将2580000元用科学记数法表示为( )A .72.5810⨯元 B .70.25810⨯元 C .62.5810⨯元 D .625.810⨯元 3.一个正方体的每个面都有一个汉字,其平面展开图如图所示,那么在该正方体中和“毒”字相对的字是( )A .卫B .防C .讲D .生 4.下列事件是必然事件的是( ) A .阴天一定会下雨B .打开电视机,任选一个频道,屏幕上正在播放篮球比赛节目C .某种彩票的中奖率为1%,买100张彩票一定中奖D .13名学生中一定有两个人在同一个月过生日 5.下列运算正确的是( )A .23a a a += B .22(3)6a a = C .623a a a ÷= D .34aa a =· 6.关于x 的二次函数2(1)2y x =--+,下列说法正确的是( ) A .图象的开口向上B .图象的顶点坐标是(12-,)C .当1x >时,y 随x 的增大而减小D .图象与y 轴的交点坐标为(0,2)7.如图所示,已知点E F 、分别是ABC △中AC AB 、边的中点,BE CF 、相交于点G ,2FG =,则CF 的长为( )A .4B .4.5C .5D .68.如图所示,正方形ABCD 的面积为12,ABE △是等边三角形,点E 在正方形ABCD 内,(第3题图)讲 卫 生防 病 毒A DE PB C A F EC B(第7题图)(第8题图) G在对角线AC 上有一点P ,使PD PE +的和最小,则这个最小值为( ) A. B. C .3 D二、填空题(每小题3分,共24分)9.一组数据4,3,5,x ,4,5的众数是4,则x = .10.如图所示,直线a b ∥,点B 在直线b 上,且AB BC ⊥,259∠=°,则1∠= 度.11.如图所示,在平面直角坐标系中,OAB △三个顶点的坐标是(00)3452O A B ,、(,)、(,).将OAB △绕原点O 按逆时针方向旋转90°后得到11OA B △,则点1A 的坐标是 . 12.在反比例函数4y x=-的图象上有两点11()A x y ,、22()B x y ,,当120x x >>时,1y 与2y 的大小关系是 .13.将一个含30°角的三角板和一个含45°角的三角板如图摆放,ACB ∠与DCE ∠完全重合,90C ∠=°,45606A EDC AB DE ∠=∠===°,°,,则EB = .14.如图所示,已知圆锥的高AO 为8cm ,底面圆的直径BC 长为12cm ,则此圆锥的侧面展开图的圆心角为 度.15.如图所示,在梯形ABCD 中,90614AD BC ABC AD AB BC ∠====∥,°,,,点M 是线段BC 上一定点,且MC =8.动点P 从C 点出发沿C D A B →→→的路线运动,运动到点B 停止.在点P 的运动过程中,使PMC △为等腰三角形的点P 有 个.16.观察下列图形(每幅图中最小..的三角形都是全等的),请写出第n 个图中最小..的三角形的个数有 个.A C Bba b 1 2 (第10题图) E BCB DA(第13题图) AB BC O(第14题图)B (第15题图)(第11题图) x三、解答题(每题8分,共16分) 17(π2)1--.18.先化简,再对a 取一个你喜欢的数,代入求值.221369324a a a a a a a +--+-÷-+-.四、解答题(每题10分,共20分)19.某学校为了进一步丰富学生的体育活动,欲增购一些体育器材,为此对该校一部分学生进行了一次“你最喜欢的体育活动”的问卷调查(每人只选一项).根据收集到的数据,绘制成如下统计图(不完整):请根据图中提供的信息,完成下列问题:(1)在这次问卷调查中,一共抽查了 名学生; (2)请将上面两幅统计图补充完整;(3)图①中,“踢毽”部分所对应的圆心角为 度;(4)如果全校有1860名学生,请问全校学生中,最喜欢“球类”活动的学生约有多少人?图② (第19题图) 图①球类 40%跳绳 其它踢毽15%20.如图所示,甲、乙两人在玩转盘游戏时,准备了两个可以自由转动的转盘A B 、,每个转盘被分成面积相等的几个扇形,并在每一个扇形内标上数字.游戏规则:同时转动两个转盘,当转盘停止后,指针所指区域的数字之和为0时,甲获胜;数字之和为1时,乙获胜.(如果指针恰好指在分割线上,那么重转一次,直到指针指向某一区域为止) (1)用树状图或列表法求乙获胜的概率;(2)这个游戏规则对甲乙双方公平吗?请判断并说明理由.五、解答题(每题10分,共20分)21.如图所示,AC 与O ⊙相切于点C ,线段AO 交O ⊙于点B .过点B 作BD AC ∥交O ⊙于点D ,连接CD OC 、,且OC 交DB 于点E.若30CDB DB ∠=︒=,.(1)求O ⊙的半径长;(2)求由弦CD BD 、与弧BC 所围成的阴影部分的面积.(结果保留π)22.由于受甲型H1N1流感(起初叫猪流感)的影响,4月初某地猪肉价格大幅度下调,下调后每斤猪肉价格是原价格的23,原来用60元买到的猪肉下调后可多买2斤.4月中旬,经专家研究证实,猪流感不是由猪传染,很快更名为甲型H1N1流感.因此,猪肉价格4月底开始回升,经过两个月后,猪肉价格上调为每斤14.4元. (1)求4月初猪肉价格下调后每斤多少元? (2)求5、6月份猪肉价格的月平均增长率.A B(第20题图) (第21题图)六、解答题(每题10分,共20分)23.如图所示,已知:Rt ABC △中,90ACB ∠=°.(1)尺规作图:作BAC ∠的平分线AM 交BC 于点D (只保留作图痕迹,不写作法); (2)在(1)所作图形中,将Rt ABC △沿某条直线折叠,使点A 与点D 重合,折痕EF 交AC 于点E ,交AB 于点F ,连接DE DF 、,再展回到原图形,得到四边形AEDF .①试判断四边形AEDF 的形状,并证明;②若84AC CD ==,,求四边形AEDF 的周长和BD 的长.24.某食品加工厂,准备研制加工两种口味的核桃巧克力,即原味核桃巧克力和益智核桃巧克力.现有主要原料可可粉410克,核桃粉520克.计划利用这两种主要原料,研制加工上述两种口味的巧克力共50块.加工一块原味核桃巧克力需可可粉13克,需核桃粉4克;加工一块益智核桃巧克力需可可粉5克,需核桃粉14克.加工一块原味核桃巧克力的成本是1.2元,加工一块益智核桃巧克力的成本是2元.设这次研制加工的原味核桃巧克力x 块. (1)求该工厂加工这两种口味的巧克力有哪几种方案?(2)设加工两种巧克力的总成本为y 元,求y 与x 的函数关系式,并说明哪种加工方案使总成本最低?总成本最低是多少元?B C A (第23题图)七、解答题(本题12分)25.已知:如图所示,直线MA NB MAB ∠∥,与NBA ∠的平分线交于点C ,过点C 作一条直线l 与两条直线MA NB 、分别相交于点D E 、.(1)如图1所示,当直线l 与直线MA 垂直时,猜想线段AD BE AB 、、之间的数量关系,请直接写出结论,不用证明;(2)如图2所示,当直线l 与直线MA 不垂直且交点D E 、都在AB 的同侧时,(1)中的结论是否成立?如果成立,请证明:如果不成立,请说明理由; (3)当直线l 与直线MA 不垂直且交点D E 、在AB 的异侧时,(1)中的结论是否仍然成立?如果成立,请说明理由;如果不成立,那么线段AD BE AB 、、之间还存在某种数量关系吗?如果存在,请直接写出它们之间的数量关系.八、解答题(本题14分)26.已知:如图所示,关于x 的抛物线2(0)y ax x c a =++≠与x 轴交于点(20)A -,、点(60)B ,,与y 轴交于点C .(1)求出此抛物线的解析式,并写出顶点坐标;(2)在抛物线上有一点D ,使四边形ABDC 为等腰梯形,写出点D 的坐标,并求出直线AD 的解析式;(3)在(2)中的直线AD 交抛物线的对称轴于点M ,抛物线上有一动点P ,x 轴上有一动点Q .是否存在以A M P Q 、、、为顶点的平行四边形?如果存在,请直接写出点Q 的坐标;如果不存在,请说明理由.(第25题图)A B E DC M N l A B ED C M N l A B C M N A B C M N 图1 图2 备用图 备用图(第26题图)2009年抚顺市初中毕业生学业考试 数学试题参考答案及评分标准(注:本参考答案只给出一种至几种解法(或证法),若用其它方法解答正确,可参考此评分标准相应步骤赋分)二、填空题(每小题3分,共24分)9.4 10.31 11.(43)-, 12.12y y > 13.4 14.216 15.4 16.14n -三、解答题(每题8分,共16分)17.解:原式=211)-- ······························································································ 6分=211-=2·········································································································· 8分18.解:原式=213(3)32(2)(2)a a a a a a a +---÷-++- ······································································ 2分 =213(2)(2)32(3)a a a a a a a +-+---+-· ······························································································· 3分 1233a a a a +-=--- ······················································································································· 4分 =33a - ···································································································································· 6分 a 取值时只要不取2,2-,3就可以. ················································································ 7分 求值正确. ······························································································································ 8分四、解答题(每题10分,共20分)19.(1)200 ·································································································································· 2分第19题图 图①球类 40% 其它 20% 踢毽15%跳绳 25%图②(2)补充图:扇形图中补充的 跳绳25% ········································································ 3分 其它20% ································································································································· 4分 条形图中补充的高为50 ·········································································································· 5分 (3)54 ···································································································································· 7分 (4)解:1860×40%=744(人). ························································································ 9分 答:最喜欢“球类”活动的学生约有744人. ··································································· 10分 20由列表法可知:会产生12种结果,它们出现的机会相等,其中和为1的有3种结果.()31P 124∴==乙获胜 ················································································································ 6分 解法二:(树状图) ·············································· 4分由树状图可知:会产生12种结果,它们出现的机会相等,其中和为1的有3种结果.()31P 124∴==乙获胜 ················································································································ 6分 (2)公平. ···························································································································· 7分()131P P 4124=== 乙获胜(甲获胜), ························································································· 8分()()P =P ∴乙获胜甲获胜 ·················································································································· 9分 ∴游戏公平. ························································································································ 10分 五、解答题(每题10分,共20分)21.解:(1)AC 与O ⊙相切于点C 90ACO ∴∠=° ·································································· 1分 BD AC ∥90BEO ACO ∴∠=∠=°12DE EB BD ∴===(cm ) ·································· 3分 30D ∠= °260O D ∴∠=∠=° ·············································································································· 4分1 1 2- 3-1- 2- 0和为 21 2- 30 1-1 31 2- 3-2141 2- 3-321(第21题图)在Rt BEO △中,2sin 602BE OB OB=°=, 5OB ∴= 即O ⊙的半径长为5cm . ··············································································· 5分 (2)由(1)可知,6090O BEO ∠=∠=°,° 30EBO D ∴∠=∠=°又CED BEO ∠=∠ ,BE ED = CDE OBE ∴△≌△ ·············································································································· 7分226025ππ5(cm )3606OBC S S ∴===阴扇·答:阴影部分的面积为225πcm 6. ····················································································· 10分 22.解:(1)设4月初猪肉价格下调后每斤x 元. 根据题意,得6060232x x-= ··································································································· 2分 解得10x = ····························································································································· 3分 经检验,10x =是原方程的解 ······························································································· 4分 答:4月初猪肉价格下调后每斤10元. ··············································································· 5分 (2)设5、6月份猪肉价格的月平均增长率为y .根据题意,得210(1)14.4y += ····························································································· 7分 解得120.220% 2.2y y ===-,(舍去) ··········································································· 9分 答:5、6月份猪肉价格的月平均增长率为20%. ······························································ 10分 六、解答题(每题10分,共20分) 23.解:(1)作图正确 ··········································································································· 1分 写出结论:射线AM 就是所要求的角平分线········································································ 2分 (2)①四边形AEDF 是菱形. ·························································································· 3分 证明:如图,根据题意,可知EF 是线段AD 的垂直平分线 则90AE ED AF FD AGE AGF ==∠=∠=,,° 由(1)可知,AD 是BAC ∠的平分线EAD DAF ∴∠=∠ AGE AGF AG AG ∠=∠= , AEG AFG ∴△≌△ ·················································· 4分AE AF ∴= AE ED DF AF ∴=== ∴四边形AEDF 是菱形. ····································································································· 5分 ②设AE x =,则8ED x CE x ==-,在Rt ECD △中,2224(8)x x +-=第23题图C BM D E F GA。