(A) माना $\Delta = \left|\begin{array}{ccc}1 & x & x^{2} \\ x^{2} & 1 & x \\ x & x^{2} & 1\end{array}\right|$.
$R_{1} \rightarrow R_{1} + R_{2} + R_{3}$ लागू करने पर:
$\Delta = \left|\begin{array}{ccc}1+x+x^{2} & 1+x+x^{2} & 1+x+x^{2} \\ x^{2} & 1 & x \\ x & x^{2} & 1\end{array}\right|$
$R_{1}$ से $(1+x+x^{2})$ उभयनिष्ठ लेने पर:
$\Delta = (1+x+x^{2}) \left|\begin{array}{ccc}1 & 1 & 1 \\ x^{2} & 1 & x \\ x & x^{2} & 1\end{array}\right|$
$C_{2} \rightarrow C_{2} - C_{1}$ और $C_{3} \rightarrow C_{3} - C_{1}$ लागू करने पर:
$\Delta = (1+x+x^{2}) \left|\begin{array}{ccc}1 & 0 & 0 \\ x^{2} & 1-x^{2} & x-x^{2} \\ x & x^{2}-x & 1-x\end{array}\right|$
$C_{2}$ और $C_{3}$ से $(1-x)$ उभयनिष्ठ लेने पर:
$\Delta = (1+x+x^{2})(1-x)(1-x) \left|\begin{array}{ccc}1 & 0 & 0 \\ x^{2} & 1+x & x \\ x & -x & 1\end{array}\right|$
चूंकि $(1-x)(1+x+x^{2}) = (1-x^{3})$:
$\Delta = (1-x^{3})(1-x) \left|\begin{array}{ccc}1 & 0 & 0 \\ x^{2} & 1+x & x \\ x & -x & 1\end{array}\right|$
$R_{1}$ के अनुदिश विस्तार करने पर:
$\Delta = (1-x^{3})(1-x) [1((1+x)(1) - (x)(-x)) - 0 + 0]$
$\Delta = (1-x^{3})(1-x) (1+x+x^{2})$
$\Delta = (1-x^{3})(1-x^{3}) = (1-x^{3})^{2}$.
अतः,परिणाम सिद्ध हुआ।