The area under a graph within an interval x \in [a,b] can be estimated by a sum of rectangles for smaller intervals of v.

Differentiation is the process of finding the derivative function from the original function. Conversely, the process of finding a function from its derivative is called anti-differentiation.

f(x) is known as the antiderivative of f^{\prime}(x).

A derivative function might have several antiderivatives (see example).