Answer
(a) 1
(b) 0
(c) undefined.
Work Step by Step
$-\frac{3\pi}{2}$ is coterminal with $-\frac{3\pi}{2}+2\pi=\frac{\pi}{2}$.
Coterminal angles intersects the unit circle at the same point.
An angle of $\frac{\pi}{2}$ radians intersects the unit circle at the point $(0,1)$. So is the angle $-\frac{3\pi}{2}$.
(a) $\sin s= y= 1$
(b) $\cos s=x=0$
(c) $\tan s=\frac{y}{x}=\frac{1}{0}$ is undefined.
