Use FTC II from single-variable calculus to prove the second part of the Fundamental Theorem of Calculus for Vector-Valued Functions.

Fundamental Theorem of Calculus for Vector-Valued Functions Part I: If r(t) is continuous on [a, b], and R(1) is an antiderivative of r(t), then S." r(t) dt = R(b) - R(a) Part II: Assume that r(t) is continuous on an open interval I and let a be in I. Then d dt r(s) ds = r(t)