# Thread: ODE - Species population modelling

1. ## ODE - Species population modelling

Hi guys,
I would like some help on this problem.

I have a quiz soon, which is on this problem set. I can't get help tomorrow as I have classes all day. I have been really busy during the last few weeks on the family farm. I have hired a personal tutor, but we don't start until after the quiz. Thus help would be much much appreciated.

I'm not exactly sure how to model this.

You are told that "if the birth rate is R then the number of births betwee difference in births between two times, $t$ and $t+ \Delta t$, is $R\Delta t$. That is, $R(t+ \Delta t)- R(t)= R\Delta t$. That should remind you of $\frac{R(t+ \Delta t)- R(t)}{\Delta t}= R$ and so of the derivative.