已知椭圆
的右焦点为
,点
在椭圆上.
![](https://img.xkw.com/dksih/QBM/2015/12/14/1572355636092928/1572355641860096/STEM/77cf2d18c42e4430a86e2a5ee28062ed.png)
(Ⅰ)求椭圆的离心率;
(Ⅱ)点
在圆
上,且
在第一象限,过
作圆
的切线交椭圆于
,
两点,求证:△
的周长是定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ec56b59d6f2654570c2b5c4fd13a05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6d6f746c2355072d914591bf60c3801.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15bf2a910999a584f47222af4cbd485c.png)
![](https://img.xkw.com/dksih/QBM/2015/12/14/1572355636092928/1572355641860096/STEM/77cf2d18c42e4430a86e2a5ee28062ed.png)
(Ⅰ)求椭圆的离心率;
(Ⅱ)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef74c4299221a967507c6a179337581a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef74c4299221a967507c6a179337581a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eebde8149009f37b9f796913f596d07.png)
更新时间:2016-12-03 21:48:39
|
【知识点】 椭圆
相似题推荐
解答题-问答题
|
困难
(0.15)
【推荐1】如图所示,已知椭圆
:
,其中
,
,
分别为其左,右焦点,点
是椭圆
上一点,
,且
.
![](https://img.xkw.com/dksih/QBM/2017/3/7/1638699921432576/1641014044647424/STEM/761c07394e15416d8ad0c4ef31abb926.png?resizew=241)
(1)当
,
,且
时,求
的值;
(2)若
,试求椭圆
离心率
的范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7aea48c44781a844b5c19191f70f61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a0c4c098615c6bc7e6dcf72e5b5201a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f9faac7fd3fd82da36110c23c377f1c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd819cecdc902a844a139bfbdedaef02.png)
![](https://img.xkw.com/dksih/QBM/2017/3/7/1638699921432576/1641014044647424/STEM/761c07394e15416d8ad0c4ef31abb926.png?resizew=241)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f5b763032c085a1e60822d8dc1b3605.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2dfb22c6f1c155747100e7536cd1abd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2f2d7c81cb44416bcdf59419637682.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/168b3e4b1d6f04226fa2687a72a268b4.png)
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解答题-问答题
|
困难
(0.15)
名校
解题方法
【推荐2】已知椭圆C:
,
、
为椭圆的左、右焦点,焦距为2
,P(
-
)为椭圆上一点.
(1)求椭圆C的标准方程;
(2)已知过点(0,-
)的直线l与C交于A,B两点;线段AB的中点为M,在
轴上是否存在定点N,使得
恒成立?若存在,求出点N的坐标;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48da128547c4cf9745e8e4b99988a3db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58db0e1f4ae4ed44ae8ad87a09b27a98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
(1)求椭圆C的标准方程;
(2)已知过点(0,-
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2063f17a7bc83cb7fb33e78d67562c4.png)
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