A firm's Total Cost function is given by the equation: TC = 4000 + 5Q + 10Q2 a. Write an expression for each of the following cost concepts: -total Fixed Cost -average Fixed Cost -Total Variable Cost -Average Variable Cost -Average Total Cost -Marginal Cost b. Is this a short-run cost curve or a long-run cost curve? Explain. c. Determine the quantity that minimizes average total cost. Demonstrate that the relationship between marginal cost and average cost holds.