## Inverse of Matrix Questions 2

In this page inverse of matrix questions 2 we are going to see solution of question 2 in the topic inverse of matrix.

Question 2

Find the inverse of the following matrix

 1 2 1 2 -1 2 1 1 -2

Solution: |A|

= 2

 -1 2 1 -2

-2

 2 2 1 -2

+1

 2 -1 1 1

|A| = 1 [2-2] - 2 [-4-2] +1 [2+1]

= 1  - 2 [-6] +1 

= 0 + 12 + 3

= 15

|A| = 15 ≠ 0

Since A is a non singular matrix. A⁻¹ exists.

minor of 1

=
 -1 2 1 -2

= [2-2]

= 0

Cofactor of 1

=  + (0)

=    0

minor of 2

=
 2 2 1 -2

= [-4-2]

= -6

Cofactor of 2

=  - (-6)

=    6

minor of 1

=
 2 -1 1 1

= [2-(-1)]

= [2+1]

= 3

Cofactor of 1

=  + (3)

=    3

minor of 2

=
 2 1 1 -2

= [-4-1]

= -5

Cofactor of 2

=  - (-5)

=    5

minor of -1

=
 1 1 1 -2

= [-2-1]

= -3

Cofactor of -1

=  + (-3)

=    -3

minor of 2

=
 1 2 1 1

= [1-2]

= -1

Cofactor of 2

=  - (-1)

=    1

minor of 1

=
 2 1 -1 2

= [4-(-1)]

= [4+1]

= 5

Cofactor of 1

=  + (5)

=    5

minor of 1

=
 1 1 2 2

= [2-2]

= 

= 0

Cofactor of 1

=  - (0)

=    0

minor of -2

=
 1 2 2 -1

= [-1-4]

= [-5]

= -5

Cofactor of -2

=  + (-5)

=    -5

inverse of matrix questions 2

co-factor matrix =

 0 6 3 5 -3 1 5 0 -5

 0 5 5 6 -3 0 3 1 -5

A⁻¹ = 1/15

 0 5 5 6 -3 0 3 1 -5

Questions

Solution

1) Find the inverse of the following matrix

 2 1 1 1 1 1 1 -1 2

Solution

3) Find the inverse of the following matrix

 6 2 3 3 1 1 10 3 4

Solution

4) Find the inverse of the following matrix

 2 5 7 1 1 1 2 1 -1

inverse of matrix questions 2

Solution

5) Find the inverse of the following matrix

 3 1 -1 2 -1 2 2 1 -2

Solution Inverse of Matrix Question2 to Inverse of a Matrix 