# How do you prove the identity tan^2x/(secx+1)= (1-cosx)/cosx?

##### 1 Answer
Feb 7, 2015

You can change:
$\tan \left(x\right)$ into $\sin \frac{x}{\cos} \left(x\right)$ and
$\sec \left(x\right)$ into $\frac{1}{\cos} \left(x\right)$
Giving:

hope it helps