1 Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.85 Safari/537.36 /rde/contents/library/ps2img/cgi-bin/eqn2gif.cgi 157.118.205.34 1442823742 2015/09/21 17:22:22 \begin{align} (1 + 2 + \cdots + n)^2 - (1^2 + 2^2 + \cdots + n^2) &= \left(\sum_{k=1}^n k \right)^2 - \sum_{k=1}^n k^2 \\ &= \{ \frac{1}{2} n(n+1) \}^2 - \frac{1}{6} n(n+1)(2n+1) \\ &= \frac{1}{4} n^2(n^2+2n+1) - \frac{1}{6} n(2n^2+3n+1) \\ &= \frac{n}{12} \left\{ (3n^3+6n^2+3n) - (4^2+6n+2) \right\} \\ &= \frac{n}{12} (3n^3+2n^2-3n-2) \end{align} 3 <IMG SRC="../cgi-cache/20150921_172158.gif"> 変換 正常に処理されました 使用できないTeXコマンドがありました \begin{align} \end{align} 20150921_172158 http://www.mech.tohoku-gakuin.ac.jp/rde/contents/library/ps2img/eqn2gif_online.html Mon Sep 21 17:22:22 2015