derivative of (x^3/6)+(1/2x)?

Question

i got (x^2/2)-(1/2x^2) is that correct?
and then wut is the (F'(x))2?...meaning the derivative squred?

if you meant (1/2)x^2 - 1/(2x^2) you are correct

I don't think they are looking for the square of the derivative, but rather the second derivative.
just differentiate again what you had in your first derivative.

no i am looking for the derivattive squared becasue the accual problem is to find the surface area and to find it i need (f(x)^2)