# Extremum

From Encyclopedia of Mathematics

A maximum or minimum value of a real-valued function. (Cf. Maximum and minimum points.) In the calculus of variations the term "extremum" is also used in the study of greatest or smallest values of a functional.

#### Comments

Cf. also Maximum and minimum of a function.

In variational calculus the term extremal for a curve on which a function(al) attains its maximum (or minimum) values is often used.

**How to Cite This Entry:**

Extremum. A.B. Ivanov (originator),

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Extremum&oldid=18848

This text originally appeared in Encyclopedia of Mathematics - ISBN 1402006098