Obtain the inverses of the matrices and
. And, hence find the inverse of the matrix
.
Let
To find: A-1, B-1 and C-1
Calculating A-1
We have,
We have to find A-1 and
Firstly, we find |A|
Expanding |A| along C1, we get
= 1(1 – 0)
= 1
Now, we have to find adj A and for that we have to find co-factors:
…(i)
Calculating B-1
We have,
We have to find B-1 and
Firstly, we find |A|
Expanding |B| along C1, we get
= 1(1 – 0) – q(0)
= 1
Now, we have to find adj B and for that we have to find co-factors:
…(ii)
Calculating C-1
Here,
⇒ C = AB
⇒ C-1 = (AB)-1
We know that,
(AB)-1 = B-1A-1
Substitute the values, we get
Ans. ,
and
.