number 91 for section 8.2

91. Sustainable Harvesting Suppose that a fish population evolves according to a logistic equation and that fish are har- vested at a rate proportional to the population size. If N() denotes the population size at time /, then dN - AN dt = IN Assume that r = 2 and K = 1000. (a) Find possible equilibria and use the graphical approach to discuss their stability, when h = 0.1. (b) Show that if h