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[函数] 函数证明

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依然饭特稀 posted 2019-8-8 10:07 |Read mode
Last edited by hbghlyj 2025-4-6 22:15已知函数f(x)=xlnx, f(x1) = f(x2)且0<x1<x2<1求证:
①2/e<x1+x2<1
②1<√x1+√x2<2/√e

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色k posted 2019-8-8 11:31
码字是不太可能了,为了日后搜索,回复几个关键词:
偏移、漂移、xlnx、x\ln x、2/e、\frac2e、2/\sqrt e、\frac2{\sqrt e}

第②问:forum.php?mod=viewthread&tid=6313
第①问类似可证。
original poster 依然饭特稀 posted 2019-8-13 09:52
没学会代码

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其妙 posted 2019-8-14 12:11
Last edited by hbghlyj 2025-4-6 22:12相关的题:
\begin{aligned}
& g(x)=x \ln x \quad g\left(x_1\right)=g\left(x_2\right)=m \quad x_2>x_1 \\
& \text { prove that: } \quad x_2-x_1>\sqrt{m e+1}
\end{aligned}

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色k posted 2019-8-14 12:15

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