Answer
Domain: $(-\infty,\infty)$
Range: $[3,\infty)$
Work Step by Step
For quadratic functions, the domain is all real numbers, also written as $(-\infty,\infty)$
Since the library function $f(x)=x^2$ has a range of $[0,\infty)$, the range of $f(x)=x^2+3$ is $[3,\infty)$