Matrices - Compositon

1. The problem statement, all variables and given/known data



a) Find the inverse of the matrix:

120

201

112



(sorry I don't know how to show a matrix more clearly on this)



b) Write A and A^-1 as a composition of matrices of the form R_ij(k), T_ij and D₂₂(k)



2. Relevant equations







3. The attempt at a solution



So I've done part (a) and ended up with the inverse as:



1/7 4/7 -2/7

3/7 -2/7 1/7

-2/7 -1/7 4/7



(sorry again)



My problem is, I don't understand part (b). Any help would be much appreciated.