Q9 of 26 Page 1

Let . Then verify the following: A(adjA) = (adjA)A = |A|I, where I is the identity matrix of order 2.

Given Data:


To Prove:


A(adjA) = (adjA)A = |A|I


Solution:


For 2 x 2, matrix adjoint is defined as






Also,





Determinant of A,




Hence, A(adjA) = (adjA)A = |A|I


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