EDIT: I found an easier way to do (iii).

![Question](https://i.stack.imgur.com/mvIZW.png)

Hi, I need help on part (i)[I know what the map is doing but can't describe it] and (iii).
I found $ M\_{ik}= (a\ \delta \_{ik} + b\ \varepsilon\_{ijk}\ n\_j ) $ (summation Convention).

$M = \begin{pmatrix} a & -bn\_{3} & bn\_{2} \\bn\_{3} & a & -bn\_{1} \\-bn\_{2} & bn\_{1} & a \end{pmatrix} $

For part (iii) one way would be to invert the matrix M. I was wondering if there is some other quicker way, maybe using suffix notation.

Thanks