名校
1 . 已知椭圆
的长轴长为4,离心率为
,左顶点为
,过右焦点
作直线与椭圆分别交于
两点(异于左右顶点),连接
.
(1)证明:
与
不可能垂直;
(2)求
的最小值;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48da128547c4cf9745e8e4b99988a3db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491fa99ce27f7343c4f6392cb6c50394.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/823aa3a403b140daf398912af4aeaff5.png)
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2 . 已知双曲线
的焦距为
,它的两条渐近线与直线
的交点分别为A,B,若O是坐标原点,
,且
的面积为
,则双曲线C的焦距为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83bf4fd84818abac17a9d21237ac5ce5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8dcc91c2ffb5571eaf944c34f5e8ffe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cb1eec1d3bd1e9fa791943b531086bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fff6c6cc2bae03407a14c04456a03e4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fe95f656b98b53f71a9d72bf0c9a4b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5991e9ec7666f533a528a4173c58f0ff.png)
A.5 | B.![]() | C.![]() | D.![]() |
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3 . 给出下列命题,其中正确的选项有( )
A.非零向量![]() ![]() ![]() ![]() ![]() ![]() |
B.若![]() ![]() |
C.等边△![]() ![]() ![]() |
D.已知向量![]() ![]() ![]() ![]() |
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