 
Summary: Math 308, Matlab assignment 4
due April 9 in class
The diary from March 26, and various Mfiles mentioned below, are posted on the class web page.
1. The file RSP.m models the evolution of interacting RockScissorsPaper populations. With the
growth parameter a = 1.1 and initial conditions R(0) = 2, S(0) = 1, P(0) = 0.5, answer the
following question: which population is the largest at the time
(a) t = 1
(b) t = 5
(c) t = 10?
You can attach the plots if you like. The easiest way to do this problem is to imitate what is done in
the diary.
2. The file Cir.m models a simple system
x (t) = y(t),
y (t) = x(t).
With initial conditions x(0) = 0, y(0) = 1, the true solution to this system is
x(t) = sin t,
y(t) = cos t.
Therefore x(t)2
+ y(t)2
= 1, and in the x  y plane one gets a circle.
