Answer:
D=(-∞,∞) Range = [0, ∞)
Explanation:
V(r) =5πr²
Firstly we have to work with π as ≈ 3.14 so that we can make it better, by doing this we reveal it more clearly its quadratic form
V(r)= 15.71r²
As there is no restriction algebraically speaking. The Domain is all the Real Line. This is a Total Function.
As for the Range, since any negative value plugged into x² will turn into a positive one we'll only have positive results for y to each entry of x. So the Range is f(x) ≥0
As you can check it below.