Definition 1.2.2: Function, Domain, and Range

Let A and B be two sets. A function f from A to B is a relation between A and B such that for each a A there is one and only one associated b B. The set A is called the domain of the function, B is called its range.

Often a function is denoted by y = f(x) or simply f(x), indicating the relation { (x,f(x)) }.

Context