Question: A manufacturer sells two goods, one at a price of $3000 a unit and the other at a price of $12,000 a unit. A quantity q1 of the first good and q2 of the second good are sold at a total cost of $4000 to the manufacturer.
(a) Express the manufacturer's profit, π, as a function of q1 and q2.
(b) Sketch curves of constant profit in the q1q2-plane for π = 10,000, π = 20,000, and π = 30,000 and the break-even curve π = 0.