4. (20 POINTS) A firm has the following cost function TC = 4* + 4q + 6400 a) Find the average cost, AC. and find the output that minimizes AC. ( (b) Show that you have a minimum. (e) Find the marginal cost, M C. (d) Show that MC = AC when AC is at its minimum. 5.(20 POINTS)The demand function for a good is: p = q2 15g + 1800 (a) Find the total revenue function and the marginal revenue function (b) Find the output which maximizes total revenue. () Show you have a maximum. A (2N POINTS) A