Answer
The domain is $\left\{x| x \ge -3\right\}$.
Work Step by Step
The square root is defined only when the radicand (number/expression inside the radical sign) is non-negative.
To find the values of $x$ for which the given expression is defined, solve the inequality $x+3 \ge 0$ to obtain:
$x+3 \ge 0
\\x+3-3 \ge 0-3
\\x \ge -3$
Thus, the domain of the given expression is the set of all real numbers greater than or equal to $-3$.
