# Math Help - find the value

1. ## find the value

Please help me to obtain the value of the following:
$\tan\left(i\log\left[\frac{a-ib}{a+ib}\right]\right)$
Thanks...

2. ## Re: find the value

Start by writing the tangent function in terms of sines and cosines, then write the sines and cosines in terms of the complex exponential. Things should simplify greatly...