The demand for coffee, Q, in pounds sold per week, is a function of the price of coffee, c, in dollars per pound and the price of tea, t, in dollars per pound, so Q = f(c, t).
(a) Do you expect f_c to be positive or negative? What about f_t? Explain.
(b) Interpret each of the following statements in terms of the demand for coffee:
f(3, 2) = 780 f_c (3, 2) = −60 f_t(3, 2) = 20