Hi, I have this problem which I don't know how to solve... I know the following identities, but I don't know how to apply them to the problem.

These are the identities I know:

cot(A)=1/tan(A)=sin(A)/cos(A)=sin(2A)/cos(2A)+1

and I also know that sin(2A)=2sin(A)cos(A) and cos(2A)=cos^2(A)-sin^2(A)

Thanks a lot!