If $ω$ is a complex cube root of unity, then the value of the determinant $Δ=\begin{bmatrix}1 & ω &ω^2\\ω & ω^2 & 1\\ω^2 & 1 & ω\end{bmatrix},$ is |
1 0 $ω^2$ $ω$ |
0 |
The correct answer is option (2) : 0 Applying $C_1→C_1+C_2+C_3<$ we have $Δ=\begin{bmatrix}1+ω+ω^2 & ω &ω^2\\ω+ω^2+1 & ω^2 & 1\\ω^2+1+ω & 1 & ω\end{bmatrix}$ $⇒Δ=\begin{bmatrix}0 & ω &ω^2\\0 & ω^2 & 1\\0 & 1 & ω\end{bmatrix}$ $[∵1+ω+ω^2=0]$ $⇒Δ=0$ $[∵C_1 $ consists of all zeroes $]$ |