$A$ is $n\times n$ matrix over $\mathbb C$. must exist that:
- $A^*A$ is diagonalizable over C
- $AA^*$ is unitary matrix
- if $A$ is not diagonalizable over $\mathbb C$ so $AA^*$ is not diagonalizable over $\mathbb C$
- $i+1$ is not eigenvalue of $A$
I know the answer is 1+4 but I really dont understand why!
- sorry for bad english