Case (i)
If
there
is one stationary solution
.
When
, the
differential equation has the form
and
the solution is
.
![[Graphics:Images/HarvestingModelProof_gr_23.gif]](../Images/HarvestingModelProof_gr_23.gif)
The solution with the initial condition
is
.
If
then
.
If
then
function x(t) has
a vertical asymptote at
and the population x(t) becomes
extinct at some time
(where
), i.
e.
.
Proof (i).
There is one real roots of the characteristic
equation
, it
is
.
Thus there is one stationary
solution
.
We will verify that
satisfies
the D. E.
.
To find the solution with the initial
condition
, proceed
as follows.
Example (i). Find
the solution to the D. E.
using
the general solution and compare it with the one found with
Mathematica.
Solution (i).
Now find the solution with the initial
condition
.
(c) John H. Mathews 2004