If $\mathrm{\alpha }$ is a root of x⁴ = 1, with negative principal argument, then principal argument of $\mathrm{\omega }$
where $\mathrm{\omega }=\left|\begin{array}{ccc}1& 1& 1\\ {\mathrm{\alpha }}^{\mathrm{n}}& {\mathrm{\alpha }}^{\mathrm{n}+1}& {\mathrm{\alpha }}^{\mathrm{n}+3}\\ \frac{1}{{\mathrm{\alpha }}^{\mathrm{n}+1}}& \frac{1}{{\mathrm{\alpha }}^{\mathrm{n}}}& 0\end{array}\right|$ (where $n\in N$) IS