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: (i) Total Fixed Cost Average Fixed Cost (iii) Total Variable Cost (iv) Average Variable Cost (V) Average Total Cost (vi) Marginal Cost (b) Determine the quantity that minimizes average total cost. Demonstrate that the predicted relationship between marginal cost and average cost holds