1. ## Proving trigonometry

Cos@/(1+tan@) + sin@/(1-cot@) = sin@ + cos @

2. ## Re: Proving trigonometry

Originally Posted by ZGOON
Cos@/(1+tan@) + sin@/(1-cot@) = sin@ + cos @
Sorry, not an identity but rather can be an equation with few points, i.e., only valid at certain points: