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[几何] 一道几何最值试题

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aishuxue posted 2014-3-26 18:24 |Read mode
Last edited by hbghlyj 2025-5-4 00:52$\angle C A B=60^{\circ}, M, N$ 在角的两边上,且 $M N=2$,以 $M N$ 为边作等边三角形 $P M N$,$P, A$ 在直线 $M N$ 异侧,求 $A P$ 的最大值.

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乌贼 posted 2014-3-26 18:58
Last edited by hbghlyj 2025-5-4 00:53点到圆的距离

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其妙 posted 2014-3-26 19:00
变式题:改为$\angle CAB=90^{\du}$,求$AP$的最大值。

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kuing posted 2014-3-26 20:15
除特殊情况外,P 的轨迹都是椭圆

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original poster aishuxue posted 2014-3-26 20:31
纯几何解法!

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乌贼 posted 2014-3-26 20:37
回复 5# kuing
为什么一定要把$P$看成动点,$A$看成定点

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isee posted 2014-3-26 20:39
回复 6# aishuxue


    3楼不是已经有了

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original poster aishuxue posted 2014-3-26 21:09
谢谢,将等边三角形固定,点$A$看成是动点!

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其妙 posted 2014-3-31 16:45
转化与化归 posted 2014-3-31 19:14
标准答案供参考。
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kuing posted 2014-3-31 19:21
回复 11# 转化与化归

这标答也太……要不要这么大费周张……写答案的太闲了吧……

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其妙 posted 2014-3-31 21:52
回复  转化与化归

这标答也太……要不要这么大费周张……写答案的太闲了吧…… ...
kuing 发表于 2014-3-31 19:21
牛笔!

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其妙 posted 2014-3-31 22:43
回复 11# 转化与化归
感谢这个资料来的及时!

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