The determinant of a matrix is how much the matrix expands or contracts space. More precisely: it's the volume of the parallelepiped spanned by the columns of the matrix. (Ditto the rows.) This, btw, is why det 0 => non-invertible: one or more spatial dimensions has collapsedhttps://twitter.com/ZachWeiner/status/1073671743846395905 …
The matrix I described above is 2 by 2, but has just a single eigenvector. So you're wrong about n x n matrices having n eigenvalues.
-
-
That's why algebraic multiplicities (2, in my example) are needed, rather than geometric multiplicities (1, in my example). This is true of any non-normal matrix, except in the trivial case with eigenvalue 1, where raising to different powers makes no difference.
-
No, the problem of missing an eigvec, and hence by your semantics missing an eigval, is not true of any non-normal matrix, only special non-generic ones (an infinitesimal perturbation will give full basis of eigvecs). e.g. [[2, epsilon][1,2]] has two eigvecs for ep \neq 0.
- 8 more replies
New conversation -
-
-
It's semantics. As I said, different conventions. You consider it an eigenvalue only if associated w/ eigenvector, so if matrix is missing an eigenvec, you consider it missing an eigenvalue. I think of the eigenvalues as the solutions to the characteristic Eq., n x n always has n
Thanks. Twitter will use this to make your timeline better. UndoUndo
-
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.