Solving Linear Differential System: Eigenvalues & Exact Solutions

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
5 replies · 2K views
aaaa202
Messages
1,144
Reaction score
2
I am studying a system described by a set of first order linear differential equations as can be seen on the attached picture. Now I know that to solve this analytically for a given N, N denoting the matrix size, one has to find the eigenvalues of the given matrix, which translates into finding the roots of an nth order polynomial, which is in general not possible.
But if you look at the matrix on the picture, which has a special structure, would it then be possible to find the exact eigenvalues of it and then find the exact solution of the system.
I should mention that the boundary conditions are simply:
x1(0) = 1, xn(0)=0, N≥n>1
If not by an eigenvalue method are there any other ways to find an exact solution?
 

Attachments

  • matrix.png
    matrix.png
    9.1 KB · Views: 499
Physics news on Phys.org
No the matrix differs does not follow the pattern in the first and last row.
 
But its still tridiagonal
 
aaaa202 said:
No the matrix differs does not follow the pattern in the first and last row.

Your matrix is not square: it has n rows and (n+1) columns. Therefore, your DE system does not make sense.
 
Oh sorry the drawing is wrong. So it is a tridiagonal matrix as described in the link above but with a_NN zero and a_12 zero. Is it possible to solve the eigenvalue equation for such a matrix exactly?