Let
A=[2436]
be a fixed 2×2 matrix.
(a) Determine, in terms of variables x,y,z,w, all 2×2 matrices
B=[xzyw]
that satisfy AB=O2×2 but are themselves non-zero.
(b) Using your result from part (a), construct one such matrix B whose entries are all integers.
(c) Verify explicitly that the pair (A,B) you have chosen in part (b) indeed produces the zero matrix when multiplied in the order AB.