If $$A = \left[ {\matrix{ 1 & { - 1} \cr { - 1} & 1 \cr } } \right]$$, then the expression A³ $$-$$ 2A² is

If $$A = \left( {\matrix{ 1 & 2 \cr 2 & 3 \cr 3 & 4 \cr } } \right)$$ and $$B = \left( {\matrix{ 1 & 2 \cr 2 & 1 \cr } } \right)$$, then which one of the following is correct?

If $$B = \left[ {\matrix{ 3 & 2 & 0 \cr 2 & 4 & 0 \cr 1 & 1 & 0 \cr } } \right]$$, then what is adjoint of B equal to?

If $$A = \left[ {\matrix{ 0 & 1 \cr 1 & 0 \cr } } \right]$$, then the matrix A is a/an