Concept:
If two functions f and g take numbers as input and produce numbers as output, two new functions may be formed by using the output of one of the functions as the input of the other. These new functions are called composite functions. Composition is denoted by , read โof,โ and the two new functions are f
g and g
f, defined as (f
g)(x) = f(g(x)) and (g
f)(x) = g(f(x)).