The population of fish, P, in a lake is a function of time, t, measured in years. The rate of change of P is given by
a. Make another graph of dp/dt on the domain [0,20].
b. Estimate the change in population on the time interval 0 ≤ t ≤ 20 years. Use 10 intervals, each lasting two years. Use rate of change data from the midpoint of each interval. Shade a matching area in your graph.