1) If P= [1α3133244] is the adjoint of a 3x 3 matrix A and |A| =4, then α is equal to A) 4 B) 11 C) 5 D) 0 Answer: Option BExplanation:Given , P= [1α3133244] ∴ |P| = 1(12-12)- α (4-6) +3(4-6) = 2α-6 ∵ P=adj(A) (given) ∴ |P|=|adj A|=|A|2, =16 (∵ |adj A|=|A|n-1) ∴ 2α-6=16 ⇒ 2α=22⇒α=11