Page 94 - DMTH201_Basic Mathematics-1

Unit 4: Determinants

Notes
0 1 1
0
Adj A 2 1 2
A 1
| | 2 1
A
1
2
2 0
2. Let A
4 1

2 0
A
| | 2 0 2 0
4 1
Cofactor of 2 = + (1) = 1

Cofactor of 0 = (4) = 4 I column
Cofactor of 4 = (0) = 0
Cofactor of 1 = + ( 2) = 2 II column

1 0
Adj A
4 2

1 0
1
Adj A 4 2 0
A 1 2
| | 2
A
2 1
1 1
3. Let A
3 4

1 1
A
| | 4 3 7 0
3 4
Cofactor of 1 = + (4) = 4
Cofactor of 1 = (3) = 3 I column
Cofactor of 3 = ( 1) = 1

Cofactor of 4 = + (1) = 1 II column
4 1
Adj A
3 1

4 1 4 1
Adj A 3 1 7 7
A 1
A
| | 7 3 1
7 7

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