If we have
solutions are
Consider the scalar product 
,
so
Therefore
Consider
The solution is described by the Fundamental Matrix
solution.
The Fundamental Matrix 
is given by
where 
is a column vector.
If 
.
Given a fundamental matrix
Consider the non-homogeneous equation
we need a solution in the following form
Then
so
because of theorem
Example 
.
Let 
for 
.
Hence
