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[不等式] 三角函数与对数的碰撞太紧了

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facebooker posted 2019-6-18 14:41 |Read mode

证明对$∀x>1,x+\sin x\geqslant 2\ln(x+1)$

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kuing posted 2019-6-18 14:47

善用搜索功能，一搜就有了：forum.php?mod=redirect&goto=findpost& … d=2856&pid=10879

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original poster facebooker posted 2019-6-18 15:07

回复 2# kuing

多谢大佬没想到是个老题。。

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isee posted 2019-6-18 16:14

可能是2019年全国卷I引出来的吧

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2025-7-15 15:20 GMT+8

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