- Find the determinant of
- $A=\left(\begin{array}{ccc}1 & x & x^2 \\\ x^2 & 1 & x \\\ x & x^2 & 1\end{array}\right)$
- Soln. $ R_1 \leftarrow R_1+R_2$
- $\therefore|A|= \left(\begin{array}{ccc} 1+x^2 & x+1 & x^2+x \\\ x^2 & 1 & x \\\ x & x^2 & 1 \end{array}\right)$
- $ R_1 \leftarrow R_1+R_3$
- Then $|A|=\left|\begin{array}{ccc}1+x+x^2 & 1+x+x^2 & 1+x+1 x^2 \\\ x^2 & 1 & x \\\ x & x^2 & 1\end{array}\right|$