Question

(i) Find the cofactor matrix of [[2, 3, 4] [1, 2, 3] [- 1, 1, 2]]​

Answer 1

Answer:

[2.-3.4] [-1.2.3] [-1.-1.2]

Step-by-step explanation:

1. C11=(-1)1+1 M11

= 1×2

= 2

2. C12=(-1)1+2 M12

=(-1)3×3

=(-1)×3

= -3

3. C13=(-1)1+3 M13

=(-1)4×4

= 1×4

=4

4. C21=(-1)2+1 M21

= (-1)3×1

= (-1)×1

= -1

5. C22=(-1)2+2 M22

=(-1)4×2

=(1)×2

= 2

6. C23=(-1)2+3 M23

= (-1)5×-3

=(-1)×(-3)

=(3)

7. C31=(-1)3+1 M31

=(-1)4×-1

=(1)×(-1)

= (-1)

8. C32=(-1)3+2 M32

=(-1)5×1

=(-1)×1

=(-1)

9. C33=(-1)3+3 M33

=(-1)6×2

=(1)×2

= 2