Mathematics & Science Learning Center
Computer Laboratory

Applications of Differential Equations

Population Dynamics

(continued from last page...)

Now you should have:

FindRoot[{(verhulst/.t->110)==75.99,
(verhulst/.t->210)==281.4},
{a, 0.02}, {b, 0.001}]

{a -> 0.0291752, b -> 0.0000876597}

It looks like we got them! Apparently our choice for a was too small, and our b choice was way too large. Now we want to plug these values of a and b back into verhulst. To do so, we use the command:

verhulst=verhulst/.%

Flip back to Mathematica and issue this command.

Let's go look at what you should have gotten...

If you're lost, impatient, want an overview of this laboratory assignment, or maybe even all three, you can click on the compass button on the left to go to the table of contents for this laboratory assignment.