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已知椭圆+=1,F1F2是它的两个焦点,P是这个椭圆上任意一点,那么当|PF1|...
已知椭圆
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102729743483599/SYS201311031027297434835006_ST/0.png)
+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102729743483599/SYS201311031027297434835006_ST/1.png)
=1,F
1F
2是它的两个焦点,P是这个椭圆上任意一点,那么当|PF
1|•|PF
2|取最大值时,P、F
1、F
2三点( )
A.共线
B.组成一个正三角形
C.组成一个等腰直角三角形
D.组成一个锐角三角形
考点分析:
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有交点,则( )
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