$$state \ the \ fundamental \ theorem \ of \ calculus \ and \ find \ the \ x \ values \ for \ x^4 + x^3 + x^2 + 2x + 1$$

You question is poorly presented and makes no sense.

what has a cone got to do with anything?

Here: https://en.wikipedia.org/wiki/Fundamental_theorem_of_calculus

Read it for yourself. I have no idea what it means.