Answer
Please see below.
Work Step by Step
Please note that a sine function $y=A\sin (Bx-C)$ has amplitude $|A|$, period $\frac{2\pi }{B}$, and phase shift $\frac{C}{B}$.
So the function $y=\sin (2x- \frac{\pi }{2})$ has amplitude $|1|=1$, period $\frac{2\pi }{2 }=\pi $, and phase shift $\frac{\frac{\pi }{2}}{2}=\frac{\pi }{4}$.
