Answer
See graph and explanations.
Work Step by Step
1. Given $y=-5sin(\frac{x}{3})$, we have amplitude $5$, period $p=\frac{2\pi}{1/3}=6\pi$.
2. Graph $y=sin(x)$ (blue), stretch horizontally by a factor of $3$, then stretch vertically by a factor of 5, then reflect around the x-axis to get $y=-5sin(\frac{x}{3})$ (red).