Cannot find nonhomogenous DE solution (should be easy?)

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Homework Statement


Determine the non-homogenous solution of the given differential equation.


Homework Equations


See 3.


The Attempt at a Solution



I have solved for the homogenous part, but as you can see in the link I am getting an unsolvable system of equations with the substitution method on the non-homogenous part. What am I doing wrong?

Capture_zpsc57ed194.jpg

 
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You have to choose an other trial function for xp, as the inhomogeneous part contains the same exponent as one of the exponents in the homogeneous part.

ehild
 
gkirkland said:

Homework Statement


Determine the non-homogenous solution of the given differential equation.


Homework Equations


See 3.


The Attempt at a Solution



I have solved for the homogenous part, but as you can see in the link I am getting an unsolvable system of equations with the substitution method on the non-homogenous part. What am I doing wrong?

Capture_zpsc57ed194.jpg

Try
<br /> x_p = a\begin{pmatrix} 1 \\ -1 \end{pmatrix} te^{-t} <br /> + b\begin{pmatrix}1 \\ -5\end{pmatrix} e^{-t}<br />
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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