# Simple integration question help

• February 18th 2011, 04:23 PM
aonin
Simple integration question help
hey guys Im a bit rusty with integrating exponentials
since the derivative of $e^{x}+e^{-x}$ is $e^{x}-e^{-x}$ how do I integrate this?

$\displaystyle\int\dfrac{e^{x}-e^{-x}}{e^{x}+e^{-x}}\,dx$

Thanks
• February 18th 2011, 04:28 PM
harish21
substitution rule:
let $u = e^x+e^{-x} \implies du = e^x-e^{-x}\;dx$
• February 18th 2011, 06:30 PM
skeeter
$\displaystyle \int \frac{f'(x)}{f(x)} \, dx = \ln|f(x)| + C$