Suppose that a company's revenue R = f (C) is a function f of the number of customers C. Suppose also that the amount spent on advertising A affects the number of customers so that C = g(A) is a function g of A.
(a) Is f * g defined? Explain.
(b) Is g * f defined? Explain.
(c) For the functions in parts (a) and (b) that are defined, identify the input (independent variable) and the output (dependent variable) and explain what the function means.