Consider a model of fishery management. State x1 is the population level of a prey species, x2 is the population level of a predator species, and x3 is the effort expended by humans in fishing the predator fish. The model is:where u is the input, y is the output, and r1 > 0 and r2 > 0. Find all equilibrium pairs (xeq, ueq) assuming the prey species does not die out and linearize the nonlinear system about the equilibrium pair (xeq, ueq) you found.