# Help Symmetric matrix

1. Dec 18, 2009

### tom08

Help!!!! Symmetric matrix

I know that all the eigenvalues of a real symmetric matrix are real numbers.
Now can anyone help out how to prove that "all the eigenvalues of a row-normalized real symmetric matrix are real numbers"? Thank you~~~

2. Dec 18, 2009

### HallsofIvy

Staff Emeritus
Re: Help!!!! Symmetric matrix

?? A "row normalized" symmetric matrix is still a symmetric matrix. Just use the same proof as for any symmetric matrix.

3. Dec 18, 2009

### CompuChip

Re: Help!!!! Symmetric matrix

4. Dec 30, 2009

### aish88

Re: Help!!!! Symmetric matrix

hi everyone plz tell me an algorithm for finding if a matrix is symmetric or not

5. Dec 30, 2009

### HallsofIvy

Staff Emeritus
Re: Help!!!! Symmetric matrix

What's wrong with the obvious one:

if $a_{ij}\ne a_{ji}$