Answer
Please see below.
Work Step by Step
Please note that a cosine function $y=A\sin (Bx-C)$ has amplitude $|A|$, period $\frac{2\pi }{B}$, and phase shift $\frac{C}{B}$.
So the function $y=\cos (x-\frac{\pi }{2})$ has amplitude $|1|=1$, period $\frac{2\pi }{1 }=2\pi $, and phase shift $\frac{\frac{\pi }{2}}{1}=\frac{\pi }{2}$.
