If , show that adj A=A.
A =
Cofactors of A
C11 = – 4 C21 = – 3 C31 = – 3
C12 = 1 C22 = 0 C32 = 1
C13 = 4 C23 = 4 C33 = 3
adj A =
=
So, adj A =
Hence, adj A = A