Inverses and Composite  are two important concept of functions.  Composite function is defined as one function  defined inside another function. Like ff(x)) or f(g(x)) etc. Concept  of inverse is interchange of variables . Inverse notations are f-1(x),g-1(x) etc. Hence interchange is inverse. Therefore function and its inverse is reflection about y = x.

 

Inverse and composite

inverse and composite