Average total cost-marginal cost functions

Question

Problem: For each of the following cost-output relationships, describe the shape (U-shape, decreasing, increasing, constant) of the average total cost and marginal cost functions

(C = total cost, Q = output):

(1) C = 42,500,000 + 2550Q

(2) C = 8.48 + 0.65Q + .00220Q²