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4792| 3
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AB,DE 是过椭圆 x^2/a^2+y^2/b^2=1 焦点 F 所作互相垂直的弦,求 1/FA+1/FB+1/FE |
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AB,DE 是过椭圆 x^2/a^2+y^2/b^2=1 焦点 F 所作互相垂直的弦,求 1/FA+1/FB+1/FE+1/FD | ||
AB,DE 是过椭圆 x^2/a^2+y^2/b^2=1 焦点 F 所作互相垂直的弦,求 1/FA+1/FB+1/FE+1/FD | ||
AB,DE 是过椭圆 x^2/a^2+y^2/b^2=1 焦点 F 所作互相垂直的弦,求 1/FA+1/FB+1/FE+1/FD
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