If and show that AB = BA = O3 × 3.
Given, A B
AB
AB ......(1)
BA
BA ......(2)
From equation 1 and 2,
AB = BA
and 
show that AB = BA = O3 × 3.
B
......(1)
......(2)
and show that AB = BA = O3 × 3. B ......(1) ......(2)