Answer
all real numbers
Work Step by Step
For $\sqrt{x^2+2}$ to be a real number, $x^2+2$ must be non-negative.
$x^2+2\geq0$
Subtract 2 from both sides of the inequality and simplify.
$x^2+2-2\geq0-2$
$x^2\geq-2$
Since $x^2$ is always non-negative, the expression is true for all real number values of x.