Question

If f(x)=x+9 and g(x)=x-9,

a) f(g(x))=
b) g(f(x))=
c) Thus g(x) is called an _____ function of f(x)

Answer 1

a) f(g(x)) = (x-9) + 9 = x
b) g(f(x)) = (x+9) - 9 = x
c) inverse function of f(x)