Brian conducted a six day study observing the affects of organic plant growth of his sprouting bean plant. Ryan found that the amount of plant food remaining decreased an equal amount each day and he use an entire 72 mL by the end of a study. Write a function rule for the  relationship between the amount of plant food remaining f(x) and the number of days that have passed X

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.