Question

Solve for X:

5sinx+2cos2x-3=0

Answer 1

cos2x=1-sin^2 x

Try that, I think you will get a quadratic equation

Answer 2

5sinx+2cos^2x-2sin^x-3=0
5sinx+2-2sin^2x-2sin^2x-3=0
4sin^2x-5sinx+1=0