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一道含对数的数列极限

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青青子衿 Posted at 2020-12-5 12:14:27 |Read mode
Last edited by 青青子衿 at 2020-12-19 21:32:00\begin{align*}
\lim_{n\to+\infty}\frac{\left(n+1\right)^2\ln\left(n+1\right)-n^2\ln\,\!n}{n\ln\,\!n}
\end{align*}

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kuing Posted at 2020-12-5 14:30:16
这有啥难的吗,稍微变个形
\[\frac{(n+1)^2\ln(n+1)-n^2\ln n}{n\ln n}=\left( 1+\frac1n \right)^2\ln\left( 1+\frac1n \right)^n\frac1{\ln n}+2+\frac1n,\]所以极限显然就是 `2`。

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