Extremum

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.