(b) The graph below shows the marginal revenue MR (dashed) and marginal cost MC (solid), in dollars per book, of printing q copies of a certain book. y (dollars per book) y=MC y = MR 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 i. For what value(s) of q in the interval [0, 20) is the cost function minimized? ii. Let (q) be Zelda's profit from printing a copies of the book. What are the critical points of (q) in the interval [0,20]? iii. For what values of q in the interval (0,20) is the profit function (9) maximized? iv. For what values of q in the interval 0,20) is the profit function () concave down? Express your answer as one or more intervals. (b) The graph below shows the marginal revenue MR (dashed) and marginal cost MC (solid), in dollars per book, of printing q copies of a certain book. y (dollars per book) y=MC y = MR 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 i. For what value(s) of q in the interval [0, 20) is the cost function minimized? ii. Let (q) be Zelda's profit from printing a copies of the book. What are the critical points of (q) in the interval [0,20]? iii. For what values of q in the interval (0,20) is the profit function (9) maximized? iv. For what values of q in the interval 0,20) is the profit function () concave down? Express your answer as one or more intervals