名校
解题方法
1 . 已知椭圆
的离心率为
,
是椭圆
上的点,长轴的左、右端点为A、B,点P为椭圆
上异于A、B的任意一点.
(1)求椭圆
的方程;
(2)设直线AP、BP的斜率分别为
,证明:
为定值;
(3)过点P作
的切线与圆
交于D、E两点,设OD、OE的斜率分别为
,问
是否为定值,若是,求出这个定值;若不是,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd486b8796b3454eab219c28ed131683.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/399b3c1136d1f0e717e95b69c4c2bc63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
(1)求椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
(2)设直线AP、BP的斜率分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90963760acac7bfad3ae03088c6c80b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b881044b5c73db6fcce110525741b02.png)
(3)过点P作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8ed863ee96007a76bb201f2781c2769.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e2d18088eecb661fd38b53f6fd0b09a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ee950caafdafed20520afb0ce328d1.png)
您最近一年使用:0次