Example 1. Solve
the second order I.V.P.
with
,
.
Use the Runge-Kutta method to compute the solution over the interval
.
Solution 1.
The D. E. can be written as
where
.
We use the substitution
and
make the second order I.V.P. into a system of first order
I.V.P.'s
,
and
,
where
,
and
,
.
Compute the Runge-Kutta solution.
The solution we seek is the first coordinate in the 2D system.
Now we can plot the solution.
![[Graphics:../Images/PendulumMod_gr_43.gif]](../Images/PendulumMod_gr_43.gif)
(c) John H. Mathews 2004