Answer
amplitude $\frac{1}{2}$, period $\pi$, vertical translation $1$ down, and phase shift $\frac{3\pi}{2}$ to the right.
Work Step by Step
Given $y=-1+\frac{1}{2} cos(2x-3\pi)=-1+\frac{1}{2} cos[2(x-\frac{3\pi}{2})]$, we can find the following: amplitude $\frac{1}{2}$, period $p=\frac{2\pi}{2}=\pi$, vertical translation $1$ down, and phase shift $\frac{3\pi}{2}$ to the right.
