question attached

The gure below shows plots of the inow and the outow of phosphorus when the the pollution level P = 15 tons per year. (a) How many equilibrium points can you identify in the model? Label each point. It will be easiest if we agree to use letters A, B,. . . , (b) At each dynamic equilibrium, estimate the stock of phosphorus in the lake (S) (this should be a different at each equilibrium). (c) Pick one equilibrium and label some value of the stock S that is near but not at that equilibrium (label it with an X your label should be on the horizontal axis). At your value of X determine which is larger: the inow or the outow? (d) Based on your answer to the previous question, what should happen to the stock of phosphorus in the lake when it is at X? Will it move toward or away from the nearby equilibrium value? - - - Outow Inow (e) Determine which equilibria are stable and which are unstable. 150 100 50