bComposite functions/b are formed when multiple functions are combined together. It is a function of a function.

For example, the functions (f(x)) and (g(x)) can be combined together to form a composite function. [ul]liPutting (g(x)) into (f(x)), i.e. (f(g(x))) forms the composite function (fg(x)). [/li]liPutting (f(x)) into (g(x)), i.e. (g(f(x))) forms the composite function (gf(x)).[/li]/ul Tip: (fg(x)) is not necessarily the same composite function as (gf(x)). The order of the functions matter.

The notation is different when both functions are the same:

(f(f(x)) = f^2(x))

Notation for composite functions:

(f(g(x))=fg(x))

(f(f(x))=f^2(x))