Short-Run Economic Costs Suppose a firm has a short-run cost equation of C(q) = 0.1q3 - 3q2 + 60q + 1000, and short-run marginal cost equation of MC(q) = .3q2 - 6q + 60, if the firm produces 25 units of output:
Use the MC(q) equation to solve for the marginal cost of the last unit produced.
What number do I use for 'q' for the final unit? Do I use 25 because it is the 25th unit produced? And if so, how is it possible to have a negative MC