Function (mathematics) - Wikipedia
https://en.wikipedia.org/wiki/Function_(mathematics)
OverviewIn calculusDefinitionNotationOther termsSpecifying a functionRepresenting a functionGeneral propertiesThe idea of function, starting in the 17th century, was fundamental to the new infinitesimal calculus. At that time, only real-valued functions of a real variable were considered, and all functions were assumed to be smooth. But the definition was soon extended to functions of several variables and to functions of a complex variable. In the second half of the 19th century, the mathematically …
DA: 14 PA: 14 MOZ Rank: 69