Let A=(abca)A = \begin{pmatrix} a & b \\ c & a \end{pmatrix}A=(acba) where bc>0b c > 0bc>0. What are the eigenvalues of AAA?
a±bca \pm \sqrt{bc}a±bc
a±ibca \pm i\sqrt{bc}a±ibc
a±bca \pm bca±bc
±a2−bc\pm \sqrt{a^2 - bc}±a2−bc