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[函数] 对数与圆各一点的距离最小值

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isee posted 2020-12-16 17:45 |Read mode
已知点$P$为函数$f\left( x \right)=\ln x$的图象上任意一点,点$Q$为圆$\left( x-\left( e+\frac 1e \right) \right)^2+y^2=1$上任意一点,则线段$PQ$的长度的最小值为(   )

A.$\frac{\sqrt{e^2+1}-e}e$        ……

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kuing posted 2020-12-16 17:47
如无意外需要目测特殊解

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original poster isee posted 2020-12-16 18:04
回复 2# kuing


    那自然是了,肯定是特殊点的,因为我算过——就是让一个同心圆与$y=\ln x$相切,容易求得此切点为$(e,1)$……

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敬畏数学 posted 2020-12-23 10:04
猜猜答案就知道。

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