If A = and B is a square matrix of order 2 such that AB=I then B=?

B=I

B = A-1 I ---------1


A-1= adj A --------- 2


= 3 x 2 – (-4) x (-1)


2


C11 = 2 C12 = 1


C21= 4 C22 = 3


Cofactor matrix A =


Adj A =


=


Putting in 2


A-1=


=


Putting in 1


B = A-1 I


= A-1


=

1