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[几何] 极点在圆锥曲线内的极线有没有适合高中生的证明

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joatbmon Posted at 2019-4-9 14:46:47 |Read mode
点$P(x_0,y_0)$在双曲线$\dfrac{x^2}{a^2}-\dfrac{y^2}{b^2}=1(a>0,b>0)$内部,过$P$作双曲线的两弦$AB,CD$,直线$AC$与$BD$交于点$Q$,则$Q$的轨迹是$\dfrac{x_0x}{a^2}-\dfrac{y_0y}{b^2}=1$,有无初等的但是计算量小一点的证明?用双曲线是不想拉成圆。曲线系可不可以?想不出来,求助。射影几何补充的概念太多了,也不太合适。

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isee Posted at 2019-7-20 09:48:14
回复 1# joatbmon


    椭圆内的,算是比较接近楼主想法了,转载,供参考blog.sina.com.cn/s/blog_54df069f0102yucj.html

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hbghlyj Posted at 2023-7-5 01:35:56
isee 发表于 2019-7-20 09:48
回复 1# joatbmon
椭圆内的,算是比较接近楼主想法了,转载,供参考blog.sina.com.cn/s/blog_54df069f0102yucj.html
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