The volume of a cylinder is given by
[tex]V=\pi hr^2[/tex]
Solving for the radius, we have
[tex]r=\sqrt{\dfrac{V}{\pi h}}[/tex]
We are given
[tex]V=47x^3,\quad h=x[/tex]
So the radius would be
[tex]r=\sqrt{\dfrac{47x^3}{\pi x}}=\sqrt{\dfrac{47x^2}{\pi}}[/tex]
