Question

Let D be the domain of the real valued function f defined by $f\left(x\right)=\sqrt{25-x^2}$. Then, write D.

Answer 1

Given function is, $f\left(x\right)=\sqrt{25-x^2}$
Since $f\left(x\right)$ is real valued, $25-x^2\le 0$
$x^2\le 25=5\le x\le +5\therefore D=[-5,5]$