Question

If A and B are square matrices of same order, then which of the following statements is/are always true? (i) (A + B)(A − B) = A² − B² (ii) AB = BA (iii) (A + B)² = A² + AB + BA + B² (iv) AB = 0 ⇒ A = 0 or B = 0

Assertion (A): If A and B are two square matrices such that AB and BA are defined, then it is not necessary that AB = BA. Reason (R): Product of two diagonal matrices of same order is commutative.