Please help!!! Cara tracked the population of fish in a pond. At the end of the first year, she counted 8 fish. Over the years, the population tripled each year.
Which equation can be used to determine the number of fish, f, after t years?

A. f=3⋅8t
B. f=3⋅8^(t−1)
C. f=8⋅3^t
D. f=8⋅3^(t−1)

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.