# Math Help - Diagonalizable matrices

1. ## Diagonalizable matrices

Give all values of k, m and n for which the following matrix, B, is orthogonally diagonalizable (you do not have to give the diagonalization);

B =
[ 1 3 2]
[k m n]
[2 4 7]

Edit:
You don't have to solve the actually numbers. But I don't know how I should solve the problem.

2. ## Re: Diagonalizable matrices

Originally Posted by fkf
Give all values of k, m and n for which the following matrix, B, is orthogonally diagonalizable (you do not have to give the diagonalization);

B =
[ 1 3 2]
[k m n]
[2 4 7]

Edit:
You don't have to solve the actually numbers. But I don't know how I should solve the problem.
Hi fkf!

Can you use the following theorem?

Spectral Theorem for Real Symmetric Matrices: An $n \times n$ matrix A is orthogonally diagonalizable if and only if A is symmetric.

If so, can you apply it?