## Integral

The integral of a real-valued
function *f* of one real variable *x*
on the interval [*a*, *b*], is
denoted by

The ∫ sign, an
elongated "S", represents integration; *a* and *b*
are the lower limit and upper limit of integration, defining the domain
of integration; *f* is the integrand, to be evaluated
as *x* varies over the interval [*a*,*b*].

If a function has an integral, it is said to be integrable. The function for which the integral is calculated is called the integrand. The region over which a function is being integrated is called the domain of integration.

Properties of Integrals:

Other Topics:

- Average of an Integral
- Area Between Curves
- Volume by Cylindrical Disks
- Volume by Cylindrical Shells

- Improper Integrals