1. The problem statement, all variables and given/known data If A and B are 2 matrices such that AB = A and BA =B, then B2 is equal to B A Zero matrix I 2. Relevant equations We can pre or post multiply a matrix on both sides of equation. 3. The attempt at a solution (AB).(BA) = A.B AB2A = A.B Pre multiply both sides by A-1 We get B2A = AB Implies B2AB = AB as (A = AB) Post multiplying by B-1 and A we get B2 = I Is this correct?