Hi I've got some maths homework and stuck on the last 3 questions.
1. Given that sinA=3/5 and cosB=12/13, where A is obtuse and B is acute, find exact values of
2. Prove cot(A+B)is identical to cotAcotB-1
3. prove that tanA+tanB is identical to sin(A+B)
I have tried all these and just get stuck .
any help would be really appreciative