PlanetPhysics/Example of Trace

For the [[../Matrix/|matrix]] $M,$

$M=\left(\begin{array}{ccc}8& 1& 6\\ 3& 5& 7\\ 4& 9& 2\end{array}\right)$

the [[../Trace/|trace]] of $M,$ $tr(M)$ is

$tr(M)=8+5+2=15$