Answer
See graph (red).
domain $[0,\infty)$, range $[0,\infty)$.
Work Step by Step
Step 1. To obtain the graph of $f(x)=4\sqrt x$ from $y=\sqrt x$, stretch the curve vertically by a factor of 4. See graph (red).
Step 2. We can find the domain $[0,\infty)$ and the range $[0,\infty)$.