Wronskian to determine lin.ind. of solutions to a system of ODEs

In summary, the conversation discusses using the Wronskian to show the linear independence of given vectors in a textbook problem. However, it is determined that the Wronskian does not apply in this case and inspection reveals that the vectors are not linearly independent.
  • #1
SithsNGiggles
186
0

Homework Statement



In my book, I'm given that ##\vec{x}_1=\left(\begin{matrix}t^2\\t\end{matrix}\right), \vec{x}_2=\left(\begin{matrix}0\\1+t\end{matrix}\right), \vec{x}_3=\left(\begin{matrix}-t^2\\1\end{matrix}\right)## are solutions. My textbook presents an algebraic way to show that the vectors are linear independent, but I was hoping to see if I can use the Wronskian to show the same result.

Homework Equations



The Attempt at a Solution



I thought this was how the Wronskian would look:
##W\left(\vec{x}_1, \vec{x}_2, \vec{x}_3\right)=

\left|\begin{matrix}

\left(\begin{matrix}t^2\\1\end{matrix}\right) & \left(\begin{matrix}0\\1+t\end{matrix}\right) & \left(\begin{matrix}-t^2\\1\end{matrix}\right)\\

\left(\begin{matrix}2t\\0\end{matrix}\right) & \left(\begin{matrix}0\\1\end{matrix}\right) & \left(\begin{matrix}-2t\\0\end{matrix}\right)\\

\left(\begin{matrix}2\\0\end{matrix}\right) & \left(\begin{matrix}0\\0\end{matrix}\right) & \left(\begin{matrix}-2\\0\end{matrix}\right)
\end{matrix}\right|##

But I couldn't see how to proceed from there, since matrix multiplication won't work. How would I find this determinant?
 
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  • #2
You can't because it doesn't make sense.

In any case, you should be able to see by inspection that the three vectors aren't linearly independent.
 
  • #3
Okay, thanks.
 

FAQ: Wronskian to determine lin.ind. of solutions to a system of ODEs

What is a Wronskian?

A Wronskian is a mathematical tool used to determine the linear independence of solutions to a system of ordinary differential equations (ODEs). It is a determinant formed by arranging the solutions of the ODEs in a specific way.

How is a Wronskian used to determine the linear independence of solutions?

The Wronskian is calculated for a set of solutions to a system of ODEs and if the determinant is non-zero, then the solutions are considered linearly independent. If the determinant is equal to zero, then the solutions are linearly dependent.

Can the Wronskian be used for any system of ODEs?

Yes, the Wronskian can be used for any system of ODEs, as long as the solutions are known. It is a useful tool for determining the linear independence of solutions and can also be used to find the general solution to a system of linear ODEs.

What are the benefits of using the Wronskian to determine linear independence?

The Wronskian provides a quick and efficient way to determine the linear independence of solutions to a system of ODEs. It also allows for the general solution to be easily found, which can be useful in solving more complex problems.

Are there any limitations to using the Wronskian?

One limitation of the Wronskian is that it can only determine the linear independence of solutions, not the linear dependence. Additionally, it may not work for systems of ODEs with non-constant coefficients or for non-linear systems.

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