Question

sin(a+b)/sin(a-b)=tana+tanb/tana-tanb
a= alpha b = beta

I can get to this from the left side,

sinacosb+cosasinb/sinacosb-cosasinb, not sure how to prove it from there.

Answer 1

(sinacosb+cosasinb)/sinacosb-cosasinb then you divide both the numerator and denominator by cosacosb, it will give you the right side

Answer 2

you should divide the top # and the bottom # by cosacosb