Is it true that the eigenvalues of AB are the same as the eigenvalues of BA?
I am pretty sure I have proving it here as well as some other proofs that may help in Linear:
I know I have this proof covering all cases, and once I find it, I will post it.
I am not sure if the red is necessarily correct.
AB and BA have the same eigenvalues iff. AB is similar to BA.
If C and D are similar matrices, then there exist S such that .