Answer
$|A|=3$, $p=\frac{2\pi}{3} $, $\phi=\frac{\pi}{3}$.
See graph.
Work Step by Step
Step 1. Given $y=3sin(3x-\pi)=3sin[3(x-\frac{\pi}{3})]$, we can find the amplitude $|A|=3$, period $p=\frac{2\pi}{3} $, and phase shift $\phi=\frac{\pi}{3}$.
Step 2. See graph.
