Example 6.  Use Picard iteration to find the solution to the system of differential equations

        [Graphics:Images/PicardIterationMod_gr_108.gif]    

Solution 6.

First define the functions  [Graphics:../Images/PicardIterationMod_gr_109.gif]  and the initial conditions  [Graphics:../Images/PicardIterationMod_gr_110.gif]  by typing:

[Graphics:../Images/PicardIterationMod_gr_111.gif]

[Graphics:../Images/PicardIterationMod_gr_112.gif]

 

Picard iteration for generating the first six approximations is started with the Mathematica command:

[Graphics:../Images/PicardIterationMod_gr_113.gif]

[Graphics:../Images/PicardIterationMod_gr_114.gif]

[Graphics:../Images/PicardIterationMod_gr_115.gif]

[Graphics:../Images/PicardIterationMod_gr_116.gif]

 

    Techniques from calculus can be used to find the solutions   [Graphics:../Images/PicardIterationMod_gr_117.gif]   and   [Graphics:../Images/PicardIterationMod_gr_118.gif].  

The first few terms of these series can be shown to match the first few terms in the Picard iterations.

[Graphics:../Images/PicardIterationMod_gr_119.gif]



[Graphics:../Images/PicardIterationMod_gr_120.gif]

Mathematica can sum the infinite series to obtain the analytic solution.

[Graphics:../Images/PicardIterationMod_gr_121.gif]


[Graphics:../Images/PicardIterationMod_gr_122.gif]



[Graphics:../Images/PicardIterationMod_gr_123.gif]


[Graphics:../Images/PicardIterationMod_gr_124.gif]

We are done!    

Aside.  The following Mathematica commands will solve the system of D. E. 's.  

[Graphics:../Images/PicardIterationMod_gr_125.gif]


[Graphics:../Images/PicardIterationMod_gr_126.gif]

 

 

 

[Graphics:../Images/PicardIterationMod_gr_127.gif]


[Graphics:../Images/PicardIterationMod_gr_128.gif]

[Graphics:../Images/PicardIterationMod_gr_129.gif]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2005