How do you verify sin(x)cos(y)+cos(x)sin(y)cos(x)cos(y)−sin(x)sin(y)=tan(x)+tan(y)1−tan(x)tan(y)?
1 Answer
May 12, 2016
Use the sum and difference identities.

Explanation:
Using the poster above:
Applying the quotient identity
Identity proved!!!! :)
Hopefully this helps!