Problem

With

1, \omega, \omega^2

as cube roots of unity, inverse of which of the following matrices exists? a.

\begin{bmatrix} 1 & \omega \\ \omega & \omega^2 \end{bmatrix}

\begin{bmatrix} \omega^2 & 1 \\ 1 & \omega \end{bmatrix}

\begin{bmatrix} \omega & \omega^2 \\ \omega^2 & 1 \end{bmatrix}

d. None of these