3. A monopolist faces the inverse demand function described by p=60-2y, where y is output. The monopolist has the cost function C(y) = 20 + 6y+ y. (a) Express the monopolist's profit as a function of output level y. (1pt) (b) Find the monopolist's profit-maximizing output level y". (3pts) (c) How much is the monopolist's maximum profit? (Ipt) 4. A perfectly competitive firm has a cost function, C(q)=3q2+2q+108. In the short run, this firm will supply a positive amount of output, as long as the market price is greater than AVC (average variable cost). In the long run, this firm will supply a positive amount of output, as long as the price is greater than its AC (average cost). a. If market price p = $50, what is the output level the firm should supply? (3pts) b. At what price will the firm stop supplying any output in the short run (this is called shutdown)? (hint: look for minimum AVC, where AVCMC) (2pts) c. Using the same cost function, at what price will the firm stop supplying any output in the long run (this is called exit)? (hint: look for minimum AC, where AC = MC) (3pts)