Find the rate of change of total revenue, cost, and prot with respect to time. Assume that R(x) and C(x) are in dollars. R(x) = 60x - 0.5)(2, C(x) = 2x + 10, when x = 30 and dxldt = 15 units per day The rate of change of total revenue is $D per day. The rate of change of total cost is $D per day. The rate of change of total prot is $|:| per day