Let
A =
[ 8 -1 -1 ]
[ -1 8 -1 ]
[ -1 -1 8 ]
(a) Find a matrix P that orthogonally diagonalizes A.
(b) Find B = P^-1AP using the (correct) answer from (a). Enter the diagonal entries of B, in order, into the answer box below. i.e., enter b11, b22, b33 (in that order).