If $\mathrm{A}=\left[\begin{array}{ccc}\mathrm{x}-\mathrm{y}& \mathrm{y}-\mathrm{z}& \mathrm{z}-\mathrm{x}\\ \mathrm{y}-\mathrm{z}& \mathrm{z}-\mathrm{x}& \mathrm{x}-\mathrm{y}\\ \mathrm{z}-\mathrm{x}& \mathrm{x}-\mathrm{y}& \mathrm{y}-\mathrm{z}\end{array}\right]$ ,then trace of A is

$trace of A= sum of the principal diagonal elements =\left(x-y\right)+\left(z-x\right)+\left(y-z\right)=0$