# help for an eigenvalue problem!

• Apr 1st 2010, 09:20 PM
huiyan55
help for an eigenvalue problem!
I am wondering if somebody can be a help to solve this problem?

Let $A \in M_n[R]$, each row of $A$ has unit length,
and $A$ is nonsingular, how to prove that $A^T A$ which is SPD has all its eigenvalues less than 2?

Thanks for any help!
• Apr 6th 2010, 06:07 AM
huiyan55
This assertion is wrong!
The problem stated above is actually not correct. Please forget about it!