grandes-ecoles 2013 QII.A.4

grandes-ecoles · France · centrale-maths2__pc Groups Group Homomorphisms and Isomorphisms
What are the matrices directly orthogonally similar to $K_2 = \left(\begin{array}{rr} 1 & 0 \\ 0 & -1 \end{array}\right)$?
What are the matrices directly orthogonally similar to $K_2 = \left(\begin{array}{rr} 1 & 0 \\ 0 & -1 \end{array}\right)$?