Let
A = [[4, 0, 1], [2, 3, 2], [1, 0, 4]].
You may take for granted that the eigenvalues of A are 5 and 3, and that a basis for the eigenspace of A corresponding to the eigenvalue 5 is
{[[1], [2], [1]]}.
Determine whether or not A is diagonalizable. If not, explain why not; if so, explicitly find an invertible matrix P and a diagonal matrix D such that A = PDP^-1 (do not compute P^-1).