题目内容
(本小题满分13分)如图,
,
分别是椭圆
(a>b>0)的左右焦点,M为椭圆上一点,
垂直于x轴,且OM与椭圆长轴和短轴端点的连线AB平行。
(1)求椭圆的离心率;
(2)若G为椭圆上不同于长轴端点任一点,求∠
取值范围;
(3)过
且与OM垂直的直线交椭圆于P、Q.![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127707408.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127723297.gif)
求椭圆的方程
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127427213.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127442215.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127473516.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127629381.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408231311276453110.gif)
(2)若G为椭圆上不同于长轴端点任一点,求∠
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127661296.gif)
(3)过
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127442215.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127707408.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127723297.gif)
求椭圆的方程
(Ⅰ)
(Ⅱ)
,
(Ⅲ)![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127817544.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127754326.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127770291.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127801247.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127817544.gif)
(1)由已知
,
∵ ![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127863462.gif)
∴
∴
,
…………3分
(2)设
,![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128051411.gif)
……6分
当且仅当m=n时,
∴
,
……………………8分
(3)![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408231311281601546.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128191742.gif)
………………………………11分
∴
,
∴ 椭圆的方程为
………………13分
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127832381.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127863288.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127863462.gif)
∴
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127895354.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127910229.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127941374.gif)
(2)设
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127988418.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128051411.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408231311280661141.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128082931.gif)
当且仅当m=n时,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128097514.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127770291.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127801247.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128144918.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408231311281601546.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128191742.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128222721.gif)
∴
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128238311.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131128253279.gif)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823131127817544.gif)
![](http://thumb.zyjl.cn/images/loading.gif)
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