The value of the determinant $\Delta=\left|\begin{array}{ccc}0 & x-y & y-z \\ y-x & 0 & z-x \\ z-y & x-z & 0\end{array}\right|$ is
Given: $\Delta=\left|\begin{array}{ccc}0 & x-y & y-z \\ y-x & 0 & z-x \\ z-y & x-z & 0\end{array}\right|$
Let $A=\left[\begin{array}{ccc}0 & x-y & y-z \\ y-x & 0 & z-x \\ z-y & x-z & 0\end{array}\right]$
$A^{T}=\left[\begin{array}{ccc}0 & x-y & y-z \\ y-x & 0 & z-x \\ z-y & x-z & 0\end{array}\right]^{T}$
$=\left[\begin{array}{ccc}0 & y-x & z-y \\ x-y & 0 & x-z \\ y-z & z-x & 0\end{array}\right]$
$=(-1)\left[\begin{array}{ccc}0 & x-y & y-z \\ y-x & 0 & z-x \\ z-y & x-z & 0\end{array}\right]$
$=-A$
Since, $A^{T}=-A$
Therefore, $A$ is a skew symmetric matrix.
Thus, $|A|=0$
$\Rightarrow\left|\begin{array}{ccc}0 & x-y & y-z \\ y-x & 0 & z-x \\ z-y & x-z & 0\end{array}\right|=0$
$\Rightarrow \Delta=0$
Hence, the value of the determinant $\Delta=\left|\begin{array}{ccc}0 & x-y & y-z \\ y-x & 0 & z-x \\ z-y & x-z & 0\end{array}\right|$ is $\underline{0}$.