Basic Properties of Integrals: Survey of Methods

Here we sum up the basic properties of integrals that are useful in calculations.

Newton integral or an indefinite integral of a given function f is the set of all antiderivatives F, we denote it

The Newton integral is linear:

The Riemann (definite) integral corresponds to the mathematical area of the region under the graph of f, which is equal to the areas of the pieces above the x-axis minus the areas of the pieces below the x-axis. Elementary geometric reasoning then suggests that

The Riemann integral is also linear. In other words, it behaves reasonably when we multiply the integrated function by a number:

It also handles addition well:

It has useful comparison properties: Let f and g be Riemann integrable functions on [a,b]. If f ≤ g on [a,b], then