Answer
$\cos \left(\frac{3\pi}{2}-\theta\right)=-\sin\theta$
Work Step by Step
Since the values of $\cos \left(\frac{3\pi}{2}-\theta\right)$ and $-\sin \theta$ are the same, the two functions are equivalent.
$\cos \left(\frac{3\pi}{2}-\theta\right)=-\sin\theta$
