If the cost function in dollars for q units of the item in Exercise 71 is C(q) = 100q + 100, find the following.
(a) The marginal cost
(b) The profit function P(q)

(c) The approximate profit from one more unit when 8 units are sold
(d) How might a manager use the information from part (c)?

Data from Exercise 71

Suppose the demand function for q units of a certain item is

where p is in dollars.

p = D(q) = 100 + 50 In q q> 1,