2楼: Originally posted by hylpy at 2016-12-07 11:57:03
\int \frac{e^{x}+e^{-x}}{(e^{x}-e^{-x})^{2}+1}dx=\int \frac{d(e^{x}-e^{-x})}{(e^{x}-e^{-x})^{2}+1}