Answer
$[-103,\infty)$
Work Step by Step
The radicand of the given function, $
g(x)=9-\sqrt{x+103}
$ is a non-negative number. Hence,
\begin{array}{l}\require{cancel}
x+103\ge0
\\\\
x\ge-103
.\end{array}
The domain is $
[-103,\infty)
.$