![在 ```\left[...\right]``` 内换行](https://linux22.com/image/459667/%E5%9C%A8%20%60%60%60%5Cleft%5B...%5Cright%5D%60%60%60%20%E5%86%85%E6%8D%A2%E8%A1%8C.png)
我想打破 之内的界限\left[...\right]
。
\documentclass[12pt] {article}
\usepackage{epsf}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{document}
\begin{align*}
\frac{\partial U}{\partial k} &=x^k\log x
\left[1-\frac{1}{(k+2)^2}x^{2}+\frac{1}{(k+2)^2(k+4)^2}x^{4}-\frac{1}{(k+2)^2(k+4)^2(k+6)^2}x^6+....\right]+x^k\\
& \left[\frac{2}{(k+2)^3}x^{2}+\frac{1}{(k+2)^2(k+4)^2}\left\{-\frac{2}{k+2}-\frac{2}{k+4}\right\}x^{4}
-\frac{1}{(k+2)^2(k+4)^2(k+6)^2}\left\{-\frac{2}{k+2}\right.\\
&\left.-\frac{2}{k+4}-\frac{2}{k+6}\right\}x^6+....\right]
\end{align*}
\end{document}
答案1
\documentclass[12pt]{article}
\usepackage{amsmath,geometry}
\usepackage{amssymb}
\begin{document}
\begin{align*}
\frac{\partial U}{\partial k} &=x^k\log x
\Biggl[1-\frac{1}{(k+2)^2}x^{2}+\frac{1}{(k+2)^2(k+4)^2}x^{4}-\frac{1}{(k+2)^2(k+4)^2(k+6)^2}x^6+\dotsb\Biggr]+x^k\\
& \Biggl[\frac{2}{(k+2)^3}x^{2}+\frac{1}{(k+2)^2(k+4)^2}\left\{-\frac{2}{k+2}-\frac{2}{k+4}\right\}x^{4}\\
&-\frac{1}{(k+2)^2(k+4)^2(k+6)^2}\left\{-\frac{2}{k+2}-\frac{2}{k+4}-\frac{2}{k+6}\right\}x^6+\dotsb\Biggr]
\end{align*}
\end{document}