In this question , we have to express the surface area of a cube in terms of volume of the cube .
The formula of volume of cube with edge length s is

First we have to solve for s, by taking cube root to both sides. That is

And the formula of surface area of cube is

Substituting the value of s, we will get

THerefore,

Domain is related to Volume here.
And Volume cant be negative or 0. So the domain is all positive real numbers .