Page 92 - DMTH201_Basic Mathematics-1

Unit 4: Determinants

Notes
1 5 6
5. A 0 7 11
5 2 4

Cofactor of 1 = + (28 + 22) = 50
Cofactor of 5 = (0 55) = 55 I column
Cofactor of 6 = + (0 35) = 35

Cofactor of 0 = ( 20 + 12) = 8
Cofactor of 7 = + (4 30) = 26 II column
Cofactor of 11 = ( 2 + 25) = 23
Cofactor of 5 = + ( 55 42) = 97
Cofactor of 2 = (11 0) = 11 III column

Cofactor of 4 = + (7 0) = 7

50 8 97
Adj A 55 26 11
35 23 7

9 1 2
6. A 0 8 1
5 1 7

Cofactor of 9 = + (56 1) = 55

Cofactor of 1 = (0 + 5) = 5 I column
Cofactor of 2 = + (0 + 40) = 40
Cofactor of 0 = ( 7 2) = 9
Cofactor of 8 = + (63 10) = 53 II column
Cofactor of 1 = (9 5) = 4
Cofactor of 5 = + ( 1 16) = 17

Cofactor of 1 = (9 0) = 9 III column
Cofactor of 7 = + (72 0) = 72

55 9 17
Adj A 5 53 9
40 4 72

2 7 3
7. A 4 10 1
3 5 8

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