1-{(sin^2)/(1+cos x)}=cos x
How?
Is this what you mean?
Prove that,
If so, then it is not as hard as you think. Everything is already changed to and , so half of the work is done.
First, multiply both sides by :
Then subtract cos x from both sides:
Add to both sides and we now have that:
This is a trigonometric identity, and therefore you have proved that: