Demand for cd players in a survey conducted by home

Question

Question: DEMAND FOR CD PLAYERS In a survey conducted by Home Entertainment magazine, it was determined that the demand equation for CD players is given by

x = f(p, q) = 900 - 9p - e^0.4q

Whereas the demand equation for audio CDs is given by

y = g(p, q) = 20,000 - 3000q - 4p

Where p and q denote the unit prices (in dollars) for the CD players and audio CDs, respectively, and x and y denote the number of CD players and audio CDs demanded per week. Determine whether these two products are substitute, complementary, or neither.