Answer
See graph.
domain $(-\infty,\infty)$, range $(2,\infty)$, H.A. $y=2$.
Work Step by Step
Step 1. To obtain the graph of $f(x)=2+3^{x/2}$ from $y=3^x$, stretch the curve horizontally by a factor of 2, then shift 2 units up. See graph.
Step 2. We can determine the domain $(-\infty,\infty)$, range $(2,\infty)$, horizontal asymptote H.A. $y=2$.