Answer
2
Work Step by Step
By Theorem 10.1, every closed-form function is continuous on its domain.
If a function is continuous, then for every a in its domain,
$\displaystyle \lim_{\mathrm{x}\rightarrow a}f(x)=f(a)$ (the limit exists and equals f(a)
$f(3)=\sqrt{3+1}=2$
(fill in the blank with "2")
