Given, A and B be matrices of order 3 × 3. |AB| = 0, We know that |AB| = |A||B| ⇒ |A||B| = 0 ⇒ either |A| = 0 or |B| = 0 or both |A| = |B| = 0. ⇒ either |A| = 0 or |B| = 0 . Hence, if A and B be matrices of order 3 × 3. If AB = 0, either |A| = 0 or |B| = 0.