Variation of Parameters on a system of Differential Eqs (Simple question)

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Homework Help Overview

The discussion revolves around solving a system of differential equations using the Variation of Parameters method, particularly focusing on the scenario of repeated roots in the complementary solution.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to confirm the correctness of their fundamental matrix derived from the complementary solution involving repeated roots. They seek validation through a simple yes or no response.

Discussion Status

The discussion appears to be ongoing, with the original poster expressing urgency for feedback on their understanding. Some participants have not yet responded to the inquiry, indicating a lack of immediate consensus.

Contextual Notes

The original poster emphasizes the importance of the confirmation, suggesting potential anxiety about their understanding of the topic. There is also a repeated request for a straightforward answer, highlighting the pressure of homework constraints.

Saladsamurai
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Homework Statement


Okay so when solving a system of D.E.s using Variation of Parameters I know that first I find the complementary solution Xc and then do a bunch a of crap after that using the fundamental matrix.

Now I just came across a problem with repeated roots, so I just want to clarify that I am correct in saying that if the complementary solution looks like this:

[tex]X_c=c_1\left(\begin{array}{c}1\\1\end{array}\right)+c_2[\left(\begin{array}{c}1\\1\end{array}\right)t+\left(\begin{array}{c}1\\0\end{array}\right)][/tex]Then the fundamental matrix looks like this:

[tex]\Phi(t)=\left(\begin{array}{cc}1 & t+1\\ 1 & t\end{array}\right)[/tex]
Just a yes or no will do... (if it's no, I am in trouble!)

Thanks!
 
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Saladsamurai said:

Homework Statement


Okay so when solving a system of D.E.s using Variation of Parameters I know that first I find the complementary solution Xc and then do a bunch a of crap after that using the fundamental matrix.

Now I just came across a problem with repeated roots, so I just want to clarify that I am correct in saying that if the complementary solution looks like this:

[tex]X_c=c_1\left(\begin{array}{c}1\\1\end{array}\right)+c_2[\left(\begin{array}{c}1\\1\end{array}\right)t+\left(\begin{array}{c}1\\0\end{array}\right)][/tex]


Then the fundamental matrix looks like this:

[tex]\Phi(t)=\left(\begin{array}{cc}1 & t+1\\ 1 & t\end{array}\right)[/tex]



Just a yes or no will do... (if it's no, I am in trouble!)

Thanks!

Does it help you to point out that

[tex]\left(\begin{array}{cc}1 & t+1\\ 1 & t\end{array}\right)\left(\begin{array}{c}c_1 \\ c_2\end{array}\right)= \left(\begin{array}{c}c_1+ c_2(t+1) \\ c_1+ c_2t\end{array}\right)[/tex]
 

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