成都七中2009年考试数学答案

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1、中小学教学资源网【www.jiaoxue.info】天天更新全部精品成都七中2009年外地生招生考试数学模拟试题参考答案及评分标准第Ⅰ卷一、单项选择（共12小题，每小题5分，满分60分）题号123456789101112答案BDBBCDAABADB第Ⅱ卷二、填空题（共4小题，每小题4分，满分16分）13．214．352015．16．4n+2三、计算题（共6小题，满分74分）17．（本小题满分12分）（1）解：原式==·······················2分==············································

2、··········2分成都七中2009年外地生招生考试数学模拟试题第7页（共5页）本资料由中小学教学资源网【www.jiaoxue.info】整理提供！中小学教学资源网【www.jiaoxue.info】天天更新全部精品当，时原式=··························2分（2）解：联立和可得········2分化简可得解方程，得········································2分当时，则一交点为当时，则一交点为综上所述，直线与抛物线的交点坐标为，·······························

3、··················2分18．（本小题满分12分）解：（1）··························4分（2）成都七中2009年外地生招生考试数学模拟试题第7页（共5页）本资料由中小学教学资源网【www.jiaoxue.info】整理提供！中小学教学资源网【www.jiaoxue.info】天天更新全部精品·································1分·············2分······················································2分（3）····

4、····························1分·········································2分19．（本小题满分13分）（1）连结。∵。∴, ,∴.∴,······························2分得，∴。又AB为直径，∴,∴。·······2分（2）延长ED交⊙于点H，连结PE。BO为切线，∴。又∵BE＝BO，∴。而,∴∽,成都七中2009年外地生招生考试数学模拟试题第7页（共5页）本资料由中小学教学资源网【www.jiaoxue.info】整理提供！中小学教学资源网【www.jiao

5、xue.info】天天更新全部精品∴,∴BE=BH,有。···················2分又由（1）知，∴，∴EF为⊙的切线。···1分（3）MN的长度不变。过N作⊙的直径NK，连结36MK。则，且，又NK＝，∴≌，∴MN＝ED。·································2分而，，∴＝5，∴。···············2分AB=16，且OD＝，∴AD＝7，BD＝9。，∴。故MN的长度不会发生变化，其长度为。························2分20．（本小题满分12分）解：（1）延长MP交AF于点H，则△B

6、HP为等腰直角三角形．BH＝PH＝130－x　DM＝HF＝10－BH＝10－(130－x)＝x－120··························1分则　y＝PM·EM＝x·[100-(x-120)]＝－＋220x······················2分由　0≤PH≤10得　120≤x≤130　因为抛物线y＝－＋220x的对称轴为x＝110，开口向下所以，在120≤x≤130内，当x＝120时，y＝－＋220x取得最大值·····2分其最大值为　y＝12000㎡　·······································

7、1分成都七中2009年外地生招生考试数学模拟试题第7页（共5页）本资料由中小学教学资源网【www.jiaoxue.info】整理提供！中小学教学资源网【www.jiaoxue.info】天天更新全部精品（2）设有a户非安置户到安置区内建房，政府才能将30户移民农户全部安置．由题意，得30×100＋120a≤12000×50%·······································1分30×4＋（12000－30×100－120a）×0.01＋×10×0.02≤150＋3a··2分解得　18≤a≤25　·················

8、·····························1分因为