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解题方法
1 . 已知椭圆C:
的离心率为
长轴的右端点为
.
(1)求C的方程;
(2)不经过点A的直线
与椭圆C分别相交于
两点,且以MN为直径的圆过点
,
①试证明直线
过一定点,并求出此定点;
②从点
作
垂足为
,点
写出
的最小值(结论不要求证明).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58a0b452fd57bbdc105589e871baa009.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ba447f2abb9bd37cc8d3f607f7e694a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8de255124598a717187ee85cb944be05.png)
(1)求C的方程;
(2)不经过点A的直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f44755c5fee4b90266eac73ad47a128.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
①试证明直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
②从点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7920d2550a6af7df3db60a33fe02c53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b68967218fdc94c817f0e3b380cce22c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e60436c1f7b5c2f6b5331548216e8077.png)
您最近一年使用:0次
2 . 已知直线
:
和圆
:
.
(1)求圆
的圆心、半径
(2)求证:无论
为何值,直线
总与圆
有交点;
(3)
为何值时,直线
被圆
截得的弦最短?求出此时的弦长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a3dec81494c38aec8d9cd53a0ed23e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd56408b9f37b5ffc720bb393440c7fc.png)
(1)求圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)求证:无论
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
您最近一年使用:0次