Investigate the qualitative behavior of a nonlinear system of differential equations

would someone be able to help me with the code format for this problem?

Answer 1

[Roger Stafford]

The matlab function 'ode45' is your friend. Read about it at:

   http://www.mathworks.com/help/matlab/ref/ode45.html

[Sam]

I have to use pplane8.. I used it and got this graph after inputting the initial conditions. the first question I have to answer is .. As t increases, describe what happens to each population. Is the aphid population ever smaller than 300, 000? Are the aphids ever eradicated? Does the ladybug population ever exceed 2 million?

because its y vs x , and I know these are functions of t but how would I find the answers to these questions? How do I read the graph