6 . (20 POINTS) A monopolist has the following cost function: TO = 693 - 40q2 + 100q + 50 (9) and faces the following demand curve for her product: p = 80 - q (10) (a) Write the firm's total revenue, TR (b) Knowing that profit II is the difference between TR and TO, write profit in terms of q. (c) Calculate the first order condition for profit maximization and solve it for the stationary values. (d) Examine each of the stationary values. Find the value of q that maximizes the monopolist's profit