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19-Tanzanite
March 27, 2021
Question

Eigenvalues and Eigenvectors

  • March 27, 2021
  • 2 replies
  • 1165 views

Hello,

What is the reason for these two different results?
(The result with Mathcad function is good)
But I think, if I am not making a mistake in the first approach, both results should be identical.

CornelBejan_0-1616875583289.png

CornelBejan_1-1616875602120.png

CornelBejan_2-1616875621872.png

CornelBejan_3-1616875632551.png

So, what am I missing, or what am I doing wrong?

2 replies

25-Diamond I
March 27, 2021

Werner_E_0-1616882220932.png

 

Werner_E_0-1616879925401.png

Mathcad also considers the case that theta is an integer multiple of pi.

You must also be aware that on contrary to the eigenvalues, the eigenvectors are not unique.

You can see this if you compare the numeric and the symbolic result of "eigenvecs([n x n - matrix]))".

 

21-Topaz II
March 30, 2021

The simplest way to proceed is the following:

eigenvalues and eigenvectors.jpg