Question

Prove the following identities.
cos(3pi/s+x)=sinx

Answer 1

`\cos \left((3\pi)/(2)-x \right)=\sin x \\ \\ =\cos \left((3\pi)/(2) \right)\cos x -\sin \left((3\pi)/(2) \right) \sin x \\ \\ =0\cos x -(-1)(\sin x) \\ \\ =\sin x`