85,000 Suppose that the demand function for a product is given by D(p) and that the price p is a function of time given by p = 2.1t + 10, where t is in days. P a) Find the demand as a function of time t. b) Find the rate of change of the quantity demanded when t= 100 days a) D(t) = (Simplify your answer.) b) What is the approximate rate of change of the quantity demanded when t= 100 days? units day (Simplify your answer. Round to three decimal places as needed.)