BY Team Aakash Byju's
f (g(x)) or (fog)(x) denotes the combination of functions f(x) and g(x), with g(x) operating first.
Let f: A -> B and g: C -> D, then the composite function, gof: A->D is defined by gof(x)=g[f(x)], provided the range(f) ∁ Domain(g)