Suppose that the total number of units produced by a worker in t hours of an 8-hour shift can be modeled by the production function P(t). P(t) = 45t + 3t2 t3 (a) Find the number of hours before production is maximized. r=J hr (b) Find the number of hours before the rate of production is maximized. That is, find the point of diminishing returns. r=x hr