Example 1. Use the Gauss-Jordan elimination method to solve the linear system  [Graphics:Images/GaussianJordanMod_gr_49.gif].  

Solution 1.

Use the menu "Input" then submenu "Create Table/Matrix/Palette" to enter matrices A and M and vector B.

[Graphics:../Images/GaussianJordanMod_gr_50.gif]



[Graphics:../Images/GaussianJordanMod_gr_51.gif]

[Graphics:../Images/GaussianJordanMod_gr_52.gif]

First form the augmented matrix  [Graphics:../Images/GaussianJordanMod_gr_53.gif].  

 

[Graphics:../Images/GaussianJordanMod_gr_54.gif]

Then perform Gauss-Jordan elimination.

[Graphics:../Images/GaussianJordanMod_gr_55.gif]




[Graphics:../Images/GaussianJordanMod_gr_56.gif]

[Graphics:../Images/GaussianJordanMod_gr_57.gif]

[Graphics:../Images/GaussianJordanMod_gr_58.gif]

[Graphics:../Images/GaussianJordanMod_gr_59.gif]

Verify the solution.

[Graphics:../Images/GaussianJordanMod_gr_60.gif]




[Graphics:../Images/GaussianJordanMod_gr_61.gif]

[Graphics:../Images/GaussianJordanMod_gr_62.gif]

[Graphics:../Images/GaussianJordanMod_gr_63.gif]

[Graphics:../Images/GaussianJordanMod_gr_64.gif]

[Graphics:../Images/GaussianJordanMod_gr_65.gif]

[Graphics:../Images/GaussianJordanMod_gr_66.gif]

We are done.

Aside.  We can compare our answer with the answer obtained by using Mathematica's built in  RowReduce  procedure.  

[Graphics:../Images/GaussianJordanMod_gr_67.gif]



[Graphics:../Images/GaussianJordanMod_gr_68.gif]

[Graphics:../Images/GaussianJordanMod_gr_69.gif]

[Graphics:../Images/GaussianJordanMod_gr_70.gif]

This agrees with our answer that was obtained with our subroutine GaussJordan[M,3].   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2004