Orthogonally diagonalize the matrix, giving an orthogonal matrix P and a diagonal matrix D . To save time, the eigenvalues are 7 and -11 .
[[-3,8,-4],[8,-3,-4],[-4,-4,-9]]
Enter the matrices P and D below. (Use a comma to separate matrices as needed. Type an exact answer for each matrix element. Do not factor out a scalar multiple. Do not label the matrices.)