Answer
The domain is the set of real numbers greater than or equal to $-4$.
Work Step by Step
The given function is
$m(x)=2\sqrt{x+4}$
The radicand cannot be negative.
So, $x+4$ is greater than or equal to zero.
$\Rightarrow x+4\geq 0$
Subtract $4$ from each side.
$\Rightarrow x+4-4\geq 0-4$
Simplify.
$\Rightarrow x\geq -4$
Hence, the domain is the set of real numbers greater than or equal to $-4$.
