If A is a square matrix of order 3, then adj A is equal to:
Answer & explanation
Correct answer: option 2
$A\,adj\, A=|A|I_{3×3}$
So appearing determinant on both side
we get, $|A\,adj\, A|=|A|^3$
$=|A||adj\, A|=|A|^3$
$⇒|adj\, A|=|A|^2$
If A is a square matrix of order 3, then adj A is equal to:
Correct answer: option 2
$A\,adj\, A=|A|I_{3×3}$
So appearing determinant on both side
we get, $|A\,adj\, A|=|A|^3$
$=|A||adj\, A|=|A|^3$
$⇒|adj\, A|=|A|^2$