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[函数] 新高考1卷导数题

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lemondian Posted at 2023-6-8 20:27:33 |Read mode
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今年导数题居然不压轴,很简单呀!
直接做就可以了。

有个问题请教一下大家:问题(2)能否用变换主元法做?

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Czhang271828 Posted at 2023-6-8 21:55:10
我觉得, 主元随便搞搞都能扔掉...
\begin{align*}
&a(e^x+a)-x>2\ln a+\dfrac{3}{2}\\
\Longleftrightarrow\quad &e^{x+\ln a}+a^2-x>2\ln a+\dfrac{3}{2}\\
\Longleftarrow\quad &1+\ln a+a^2>(a-1)+\ln a+\dfrac{3}{2}\\
\Longleftrightarrow\quad &a^2>a-\dfrac{1}{2}\\
\Longleftrightarrow\quad &a^2-a+\dfrac{1}{4}>-\dfrac{1}{4}.
\end{align*}

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乃思!  Posted at 2023-6-8 21:57

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kuing Posted at 2023-6-8 21:59:02
确实太弱了,考生们估计会觉得当初刷那么多导数难题白刷了

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命题人有意等待大神们加强吧?!  Posted at 2023-6-8 22:19

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