I need to proof:(adsbygoogle = window.adsbygoogle || []).push({});

A in normal matrix if and only if [tex]trace(A^*A)=|t_1|^2+...|t_n|^2[/tex]

where [tex]t_1,...,t_n[/tex] are the characteristic roots of A.

I have a problem only with the second direction:

[tex]trace(A^*A)=|t_1|^2+...|t_n|^2[/tex] --> A is normal.

can you help me ?

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# Proof of normal matrix criterion

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