Page 99 - DMTH201_Basic Mathematics-1

Basic Mathematics – I

Notes
1 1 1
2. Let A 2 1 0
3 2 1

A
| | 1(1 0) 1(2 0) 1(4 3) 4 0.
Cofactor of 1 = + (1 0) = 1
Cofactor of 1 = (2 0) = 2 I column
Cofactor of 1 = + (4 3) = 1
Cofactor of 2 = ( 1 2) = 3

Cofactor of 1 = + (1 3) = 2 II column
Cofactor of 0 = (2 + 3) = 5
Cofactor of 3 = + (0 1) = 1

Cofactor of 2 = (0 2) = 2 III column
Cofactor of 1 = + (1 + 2) = 3

1 3 1
Adj A 2 2 2
1 5 3

1 1 1 1 3 1
A (Adj A ) 2 1 0 2 2 2
3 2 1 1 5 3

1 2 1 3 2 5 1 2 3
2 2 0 6 2 0 2 2 0
3 4 1 9 4 5 3 4 3

4 0 0
0 4 0
0 0 4

1 0 0
4 0 1 0
0 0 1

4 ( 4)
A
I
A
I
A
Similarly, we can verify that (Adj ) .
I
A
A
(Adj ) (Adj ) I
A
A
A
A
A
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