All of these problems involve the Fundamental Theorem of Calculus, part 1.
When you integrate, you will get a
. What happens to this when you then take the derivative?
Compare and contrast part (a) with part (b). The answers will NOT be identical.
The Fundamental Theorem of Calculus, part 1 states that the derivative of an INDEFINITE integral is the same as the original function.
But this is a DEFINITE integral: Remember to multiply by the derivative of the bounds.