《转》LaTeX技巧207：使用align环境输入多行公式的技巧

转自：http://blog.sina.com.cn/s/blog_5e16f1770100gror.html

align是输入多行公式中最好用的环境，仅仅是个人浅见，因为他的对齐非常灵活，如果大家需要非常灵巧的对齐方式的多行公式，建议使用align环境，对应的也还有align*和aligned等等类似的环境，这里不再详述。下文提供代码，尽展其风姿绰约。
演示效果图：






演示代码：
\documentclass{article}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{266.0pt}
\usepackage{CJK}
\usepackage{amsmath}

\begin{CJK}{GBK}{song}
\begin{document}

\begin{align}
<wbr>(a + b)^3<wbr>&amp;= (a + b) (a + b)^2<wbr><wbr><wbr><wbr><wbr><wbr><wbr>\\<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;= (a + b)(a^2 + 2ab + b^2) \\<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;= a^3 + 3a^2b + 3ab^2 + b^3<br> \end{align}<br> \begin{align}<br><wbr>x^2<wbr>+ y^2 &amp; = 1<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>\\<br><wbr>x<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp; = \sqrt{1-y^2}<br> \end{align}<br> This example has two column-pairs.<br> \begin{align}<wbr><wbr><wbr>\text{Compare }<br><wbr>x^2 + y^2 &amp;= 1<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;<br><wbr>x^3 + y^3 &amp;= 1<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>\\<br><wbr>x<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;= \sqrt<wbr><wbr>{1-y^2} &amp;<br><wbr>x<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;= \sqrt[3]{1-y^3}<br> \end{align}<br> This example has three column-pairs.<br> \begin{align}<br><wbr><wbr><wbr>x<wbr><wbr><wbr>&amp;= y<wbr><wbr><wbr><wbr><wbr>&amp; X<wbr>&amp;= Y<wbr>&amp;<br><wbr><wbr><wbr><wbr><wbr>a<wbr>&amp;= b+c<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>\\<br><wbr><wbr><wbr>x'<wbr><wbr>&amp;= y'<wbr><wbr><wbr><wbr>&amp; X' &amp;= Y' &amp;<br><wbr><wbr><wbr><wbr><wbr>a' &amp;= b<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>\\<br><wbr>x + x' &amp;= y + y'<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;<br><wbr>X + X' &amp;= Y + Y' &amp; a'b &amp;= c'b<br> \end{align}<br><br> This example has two column-pairs.<br> \begin{flalign}<wbr>\text{Compare }<br><wbr>x^2 + y^2 &amp;= 1<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;<br><wbr>x^3 + y^3 &amp;= 1<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>\\<br><wbr>x<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>&amp;= \sqrt<wbr><wbr>{1-y^2} &amp;<br><wbr>x<wbr><wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>