初三上学期数学试卷

初三上学期数学试卷 一. 选择题（共12小题，第1、2小题每题3分，3~12小题每题4分，共46分） 在每小题给出的四个备选答案中，只有一个是符合题目要求的。请把正确结论的代号写在题后的括号内。 1. 点A（1，3）关于原点的对称点A’的坐标为（ ） A. （3，1） B. （1，-3） C. （-1，3） D. （-1，-3） 2. 函数 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image002.gif" \* MERGEFORMATINET 
中，自变量x的取值范围为（ ） A.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image004.gif" \* MERGEFORMATINET 
 B.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image006.gif" \* MERGEFORMATINET 
 C.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image008.gif" \* MERGEFORMATINET 
 D.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image010.gif" \* MERGEFORMATINET 
 3. 如图所示，已知点A在反比例函数的图象上，那么该反比例函数的解析式为（ ） A.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image012.gif" \* MERGEFORMATINET 
 B.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image014.gif" \* MERGEFORMATINET 
 C.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image016.gif" \* MERGEFORMATINET 
 D.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image018.gif" \* MERGEFORMATINET 
  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image019.gif" \* MERGEFORMATINET 
 4. 方程 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image021.gif" \* MERGEFORMATINET 
的根的情况为（ ） A. 有两个不相等的实数根 B. 有两个相等的实数根 C. 没有实数根 D. 无法确定根的情况 5. 以下命题正确的是（ ） A. 圆的切线一定垂直于半径 B. 圆的内接平行四边形一定是正方形 C. 直角三角形的外心一定也是它的内心 D. 任意一个三角形的内心一定在这个三角形内 6. 一种药品经过两次降价，由每盒60元调至52元，若设平均每次降价的百分率为x，则可列出关于x的方程为（ ） A.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image023.gif" \* MERGEFORMATINET 
 B.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image025.gif" \* MERGEFORMATINET 
 C.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image027.gif" \* MERGEFORMATINET 
 D.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image029.gif" \* MERGEFORMATINET 
 7. 已知抛物线 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image031.gif" \* MERGEFORMATINET 
的部分图象如图所示，那么图象再次与x轴相交时的坐标为（ ） A. （5，0） B. （6，0） C. （7，0） D. （8，0）  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image032.gif" \* MERGEFORMATINET 
 8. 圆O的半径为4cm，圆P的半径为1cm，若圆P与圆O相切，则O、P两点的距离（ ） A. 等于3cm B. 等于5cm C. 等于3cm或5cm D. 介于3cm与5cm之间 9. 如图所示，直线MN与△ABC的外接圆相切于点A，AC平分 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image034.gif" \* MERGEFORMATINET 
，如果AN=6，NB=4，那么弦AC的长为（ ） A. 4 B. 5 C. 6 D. 9  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image035.gif" \* MERGEFORMATINET 
 10. 圆O1的半径为5，圆O2的半径为1，若 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image037.gif" \* MERGEFORMATINET 
，则这两圆的外公切线的长为（ ） A. 4 B.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image039.gif" \* MERGEFORMATINET 
 C.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image041.gif" \* MERGEFORMATINET 
 D. 6 11. 如图所示，在正方形网格中，角α、β、γ的大小关系是（ ） A.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image043.gif" \* MERGEFORMATINET 
 B.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image045.gif" \* MERGEFORMATINET 
 C.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image047.gif" \* MERGEFORMATINET 
 D.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image049.gif" \* MERGEFORMATINET 
  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image050.gif" \* MERGEFORMATINET 
 12. 一次函数 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image052.gif" \* MERGEFORMATINET 
的图象在 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image054.gif" \* MERGEFORMATINET 
的一段都在x轴的上方，那么a的取值范围一定是（ ） A.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image056.gif" \* MERGEFORMATINET 
 B.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image058.gif" \* MERGEFORMATINET 
 C.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image060.gif" \* MERGEFORMATINET 
 D.  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image062.gif" \* MERGEFORMATINET 
   二. 填空题（共6个小题，每小题3分，共18分） 13. 小明用计算器求得 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image064.gif" \* MERGEFORMATINET 
的值约为0.4142，那么 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image066.gif" \* MERGEFORMATINET 
的值应为____________。 14. 方程 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image068.gif" \* MERGEFORMATINET 
的两个实数根分别为 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image070.gif" \* MERGEFORMATINET 
的值为___________。 15. 如图所示，AB和CD为圆O的两条直径，弦 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image072.gif" \* MERGEFORMATINET 
， INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image074.gif" \* MERGEFORMATINET 
的度数为40°，则 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image076.gif" \* MERGEFORMATINET 
的度数为____________。  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image077.gif" \* MERGEFORMATINET 
 16. 据报载，2004年美国正、副总统的四位竞选人是历届角逐美国总统宝座最富有的一群候选人，2003年他们的家庭年收入与普通居民家庭年收入对比表如图所示，那么家庭年收入最高的竞选人是_________，他的家庭年收入比普通居民家庭年收入高出_________万美元。  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image078.gif" \* MERGEFORMATINET 
 17. 将二次函数 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image080.gif" \* MERGEFORMATINET 
化成 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image082.gif" \* MERGEFORMATINET 
的形式为_____________。 18. 如图所示，沿AC方向开山修路，为了加快施工速度，要在小山的另一边同时施工，从AC上的一点B取 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image084.gif" \* MERGEFORMATINET 
， INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image086.gif" \* MERGEFORMATINET 
，当开挖点E离D________米时，恰好使A、C、E成一条直线。  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image087.gif" \* MERGEFORMATINET 
   三. （共3个小题，其中19、20小题各5分，21小题6分，共16分） 19. 用换元法解方程 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image089.gif" \* MERGEFORMATINET 
   20. 已知：如图所示，等腰三角形ABC中，底边BC=12， INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image091.gif" \* MERGEFORMATINET 
，求出底边上的高AD的长。  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image093.gif" \* MERGEFORMATINET 
 21. （1）解方程组 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image095.gif" \* MERGEFORMATINET 
 （2）已知：如图所示，圆O的圆心为原点，半径为1，请在图中画出一次函数 INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image097.gif" \* MERGEFORMATINET 
的图象，并写出它与圆O的交点坐标（无需过程）；  INCLUDEPICTURE "http://res.tongyi.com/resources/old_article/educa/unvisity/tiku/c3/sx/8.files/image099.gif" \* MERGEFORMATINET 
 （3）你能发现（1）中方程组的解与（2）中交点坐标之间的关系吗？请写出你的发现，不用说明理由。   四. （本题满分6分） 22. 已知：如图所示，△ABC的AB边上一点D满足AB=3AD，点P在△ABC的外接圆上， INCLUDEPICTURE "http://res.tongyi.com/res