extremální

Extremální is a Czech adjective meaning pertaining to an extreme or to an extremum—the maximum or minimum of a quantity. It is used to describe states, values, or objects located at the end of a range or that realize an extremum. In everyday Czech, the more common synonym is extrémní, but extremální appears frequently in technical and scientific writing, especially in mathematics, physics, and engineering, where it signals a formal relation to extrema.

Etymology: The word is formed from the noun extremum (extreme point) with the adjective-formation suffix -ální. It shares roots with Latin extremus and the French extrême, and with English extreme.

In mathematical usage, extremální is common in phrases such as extremální hodnota (extreme value), extremální bod or extremal point (the point at which a function attains an extremum), and extremální problém (an extremal or variational problem). The related noun extrémál may denote an object that attains such an extremum, while extremum is the general term for a maximum or minimum.

In broader use, extremální describes any situation or property at an extreme degree or intensity; in casual language extrémní is often preferred, but extremální remains standard in precise or formal technical prose.