linguistic:voice_change
Real function

A real function is a function from a subset of R {\displaystyle \mathbb {R} } to R, {\displaystyle \mathbb {R},} where R {\displaystyle \mathbb {R} } denotes as usual the set of real numbers. That is, the domain of a real function is a subset R {\displaystyle \mathbb {R} }, and its codomain is R. {\displaystyle \mathbb {R}.} It is generally assumed that the domain contains an interval of positive length.