-1= adj A --------- 1 = 3 x 2 – (1) x (-1) 7C11 = 3 C12 = -1C21= 1 C22 = 2Cofactor matrix A = Adj A =’= Putting in 1A-1= =

Q41 of 98 Page 314

If A=, then A^-1=?

^-1= adj A --------- 1

= 3 x 2 – (1) x (-1)

C₁₁ = 3 C₁₂ = -1

C₂₁= 1 C₂₂ = 2

Cofactor matrix A =

Adj A =’

Putting in 1

A^-1=

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

If A and B are invertible square matrices of the same order then (AB)^-1=?

If │A│=3 and A^-1=then adj A=?

If A is an invertible matrix and A^-1 = then A=?

If A=, then A-1=?