Fundamental theorem of calculus proof
This section of Calculus math help discusses
the fundamental theorem of calculus proof. There are formal
proofs of the fundamental theorem of calculus and the informal
proof of the fundamental theorem of calculus. This section
deals with the informal fundamental theorem of calculus proof
so that calculus students may understand how the fundamental
theorem of calculus was derived.
Recall the definition of the
derivative
By the definition of the derivative:

exists and that this limit equals f(x).
x and x increment illustration
For illustration of the fundamental theorem
of calculus proof, lets assume that the function f9x0 has
positive values on the interval [a,b] so that an integral can
be thought of as representing an area under the graph of f.
Think of x as representing some point between a and b. Think of
h as representing some small positive number such that x + h is
also between a and b and is a little bit to the right of x. The
picture of this illustration is shown below.

|