profit-maximizing? 2. Suppose that the firm has the following production function: f(1 1,12) = ] +12 . Suppose all input and output markets are perfectly competitive (i.e., the firm is a price taker in all markets). Let the input price vector be (w1,W2) > 0. (a) Is this production function DRS, CRS or IRS? (b) Derive the cost function and the marginal cost function. Is the marginal cost function increasing or decreasing with the output? (c) Suppose that in the short run, the amount of input 2 is fixed at x5 =1. Derive the short-run cost function, and determine which part of the function is the variable costs and which part is the fixed costs