Let A be a 3 × 3 matrix such that a d j a d j a d j . A = 12 4 . Then A - 1 a d j A is equal to

Question

Let A be a 3 × 3 matrix such that a d j a d j a d j . A = 12 4 . Then A - 1 a d j A is equal to, 2 3, 6, 12, 1

MARKS App · Accepted Answer

Given equation is a d j a d j a d j . A = 12 4 ⇒ A ( n - 1 ) 3 = 12 4 ∵ n = 3 ⇒ A ( 3 - 1 ) 3 = 12 4 ⇒ A 8 = 12 4 ⇒ A 2 = 12 ⇒ A = 2 3 Now, A - 1 a d j A = A - 1 . a d j A = 1 A × A 3 - 1 = A = 2 3

Search any question & find its solution

Looking for more such questions to practice?