Finding the Domain and Range

We cannot take the square root of a negative number, so the value inside the radical must be nonnegative.

The domain of $f\left(x\right)$ is $[-4,\infty ).$

We then find the range. We know that $f\left(-4\right)=0,$ and the function value increases as $x$ increases without any upper limit. We conclude that the range of $f$ is $[0,\infty ).$