Answer
(a) domain $[-5,\infty)$, range $(-\infty,\infty)$.
(b) not a function.
Work Step by Step
(a) Given $y^2-x=5$, we have $x=y^2-5$ and since $y^2\geq0$, we can find its domain as $[-5,\infty)$, range as $(-\infty,\infty)$.
(b) We can rewrite the equation as $y^2=x+5$ and $y=\pm\sqrt {x+5}$ which does not represent a function.
