Lec 27 MIT 18.03 Differential Equations, Spring 2006
As a matter of fact, it plots them very accurately. But it is something you also need to learn to do yourself, as you will see when we study nonlinear equations. It is a skill. And since a couple of important mathematical ideas are involved in it, I think it is a very good thing to spend just a little time on, one lecture in fact, plus a little more on the problem set that I will give out. The last problem set that I will give out on Friday. I thought it might be a little more fun to, again, have a simple-minded model. No romance this time. We are going to have a little model of war, but I have made it sort of sublimated war. Let's take as the system, I am going to let two of those be parameters, you know, be variable, in other words. And the other two I will keep fixed, so that you can concentrate on them better. I will take a and d to be negative 1 and negative 3. And the other ones we will leave open, so let's call this one b times y, and this other one will be...