Answer
$[-1,\ \infty)$
Work Step by Step
We are given:
$f(x)=\sqrt{x+1}$
The domain of a function consists of all values that $x$ is allowed to have. In this case, we can not take the square root of a negative number:
$x+1\geq 0$
$ x\geq-1$
Therefore, the domain is: $[-1,\ \infty)$
