Answer
The graphs appear to coincide.
Work Step by Step
Please note that$$\cos (\alpha - \beta )= \cos \alpha \cos \beta + \sin \alpha \sin \beta .$$So we have$$\cos( \frac{3\pi }{2}-x)= \cos \frac{3\pi }{2} \cos x + \sin \frac{3\pi }{2} \sin x=-\sin x.$$
