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[不等式] 2x+y+2z=xyz

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tommywong Posted at 2014-7-16 08:41:10 |Read mode

正数x,y,z,2x+y+2z=xyz
求3x+y+z的最值

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kuing Posted at 2014-7-16 14:45:11

无最大，最小为三次方程的根

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滋兰树慧 Posted at 2014-7-16 19:40:38

回复 2# kuing

能说具体点吗？

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kuing Posted at 2014-7-16 19:44:17

用拉格朗日乘数法试试……

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kuing Posted at 2014-7-16 21:23:31

改一下系数还是可以做的，比如说改成 2x+y+z

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