Solving ODE45 for a system with x'=-axy, y'=axy-by, z'=by

[mooberrymarz]

Hi! I have hand in an assigment in like four hours and part of it involves solving a IVP. We have to use the built in function ODE45. the system of equations are as follows.

x'(t)=-axy
y'(t)=axy-by
z'(t)=by

Use step length 1 and solve the ivp numerically for the following values of a,b
a=0.00001, b=0.25
a=0.0002, b=0.10

I know its easy but i can't get it to work. Please help me.

 

[enigma]

Can you post your code so far, please?