Answer
See graph.
$(-\infty,\infty)$, $[-1,5]$.
Work Step by Step
Step 1. See graph for $y=-3cos(\frac{\pi}{4} x)+2$ with key points or transform from $y=cos(x)$ (stretch horizontally by a factor of $\frac{4}{\pi}$, stretch vertically by a factor of 3, reflect across the x-axis, then shift 2 units up.)
Step 2. Based on the graph, we can determine the domain as $(-\infty,\infty)$ range as $[-1,5]$.
