Answer
$[-4, +\infty)$
Work Step by Step
The radical function is defined for all real numbers $x$ for which the value of the radicand (which in this case of $x+4$) is greater than or equal to 0.
To find these numbers, solve the inequality $x+4 \ge 0$ to obtain:
$\begin{array}{ccc}
&x+4 &\ge &0
\\&x+4-4 &\ge &0-4
\\&x &\ge &-4\end{array}$
Thus, the domain of the given function is the set of real numbers greater than or equal to $-4$.
In interval notation, the domain is $[-4, +\infty)$.
