24.(本题满分10分)
,2). 如图,在平面直角坐标系中,OB OA,且OB 2OA,点A的坐标是( 1
(1)求点B的坐标;
(2)求过点A、O、B的抛物线的表达式;
(3)连接AB,在(2)中的抛物线上求出点P,使得S△ABP S△ABO.
25.(本题满分12分) 问题探究
(1)请在图①的正方形ABCD内,画出使 APB 90°的一个点P,并说明理由. ..(2)请在图②的正方形ABCD内(含边),画出使 APB 60°的所有的点P,并说明理..由. 问题解决
(3)如图③,现在一块矩形钢板ABCD,AB 4,BC 3.工人师傅想用它裁出两块全等的、面积最大的△APB和△CP D钢板,且 APB CP D 60°.请你在图③中画出符合要求的点P和P ,并求出△APB的面积(结果保留根号). D C D C D C
A B A B A B
③ ② ① (第25题图)
2009年陕西省初中毕业学业考试
数学试题参考答案
A卷
一、选择题(共10小题,每小题3分,计30分)
1 2 3 4 5 6 7 8 9 10 题号
C A A D D C B C B A卷答案 B
1 2 3 4 5 6 7 8 9 10 题号
A D C A B B A B C B卷答案 D
二、填空题(共6小题,每小题3分,计18分)
11.2 12.133° 13. 14.42 15.60 16.4 三、解答题(共9小题,计72分) 17.(本题满分5分) 解:(x 2)2 (x2 4) 3. ························································································ (2分)
4x 5.
5x . ······················································································· (4分)
4
经检验,x
5
是原方程的解. ···················································································· (5分) 4
B
(第19题答
项
18.(本题满分6分)
证明: 四边形ABCD是平行四边形, AB DC,AB∥DC.
FAE D, F ECD. ············ (3分) 又 EA ED,
△AFE≌△DCE. ······························· (5分) AF DC. AF AB. ············································· (6分) 19.(本题满分7分) 解:(1) 13 26% 50,
········· (2分) 本次被调查的人数是50. ·
补全的条形统计图如图所示. ······· (4分)
D
C