Question

Polar bears and walruses have a complex dynamic relationship: the polar bears sometimes prey on the walruses, but multiple walruses together can fend off a polar bear attack, and in some cases even injure or kill the bear. The following system of differential equations attempts to model the populations of walruses (W) and polar bears (P): SW' = 14W – 2W2 – 3WP P' = 6P - 3p2 +8WP - 2W2P (a) Plot the nullclines of this system. Then use the nullclines to get a rough sketch of the vector field of the system. Be sure to label your axes! Note: You may use a graphing calculator or online graphing tool such as Desmos or CoCalc to help you graph the nullclines. (b) Based on your work in part (a), list all of the equilibrium points of this model, and determine (as well as you can) the type of each one. (Remember: Be specific! It may not be enough to just call an equi- librium point unstable. On the other hand, if there is not enough information to classify an equilibrium point completely, you may say so.)

Answer 1

@netc3). birch data, 92 ཞེ །（12) ） * (\༽ ཞེD ： T 19） ། <༢ ར༨）་ （༢༽ ལ་) 0 2 (3) -32% ·འདT Cey) ++27 [') ༤༢、（12） ལྟར2 (༢༽-D ： ངའི ད ༣ 2༢༢）. ནད - ནོ） ༼ ་ ༢] ༼༣] [༢] ཚ » ལརིག ༧ ཀསུ ཀ ༦༨༧） - ( ཏུ ལ ） ཀ ༦/༢) ཀྱི(བོ) + (ཁ ༽ ད) ་ །