Practicing Success
Let AX=B be a system of n simultaneous linear equations with n unknowns. Statement-1: If $|A|=0$ and (adj A) B ≠ 0, the system is consistent with infinitely many solutions. Statement-2: $A (adj\, A) =|A| I$ |
Statement-1 is True, Statement-2 is true; Statement-2 is a correct explanation for Statement-1. Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for Statement-1. Statement-1 is True, Statement-2 is False. Statement-1 is False, Statement-2 is True. |
Statement-1 is False, Statement-2 is True. |
We have, $AX = B$, where $|A|=0$ $⇒(adj\, A) (AX) = (adj\, A) B$ $⇒((adj\, A) A) X = (adj\, A) B$ $⇒(|A|I) X=(adj\, A) B$ $[∵ A (adj\, A) =|A| I]$ $⇒|A|X = (adj\, A) B$ Clearly, it is not true when $|A|=0$ and (adj A) B ≠ 0. So, the system is inconsistent. Hence, statement-2 is true and statement-1 is false. |