Fundamental Theorem of Calculus

The applet calculates the change in antiderivative of a function f over an interval [a,b]. Definite integral can be guessed by using the slider. The goal is to observe that the change equals value of the definite integral
Fundamental theorem sets up a relation between definite integral and antiderivative leading to the concept of indefinite integral and use of certain techniques to calculate definite integral. For more on fundamental theorem of calculus check my online book "Flipped Classroom Calculus of Single Variable"