3. Puzzle Piece #3: Suppose a firm has production function: q = 210.510.5 where K is fixed at 9 units in the short-run, with r = 2 and w = 18. (a) Derive the firm's short-run total cost function. (b) Sketch the short-run TC and VC curves on the same graph. (c) Derive and sketch the ATC and MC curves on the same graph. Be sure to indicate where they intersect! (d) Suppose that there are a total of 3 firms identical to the one in this question. If their individual short-run supply curves are equal to their marginal cost curve, what is the equation for the market supply curve