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Using cofactors of elements of second row, evaluate |A|, where A = [538201123] - Mathematics

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प्रश्न

Using cofactors of elements of second row, evaluate |A|, where A = `[(5, 3, 8),(2, 0, 1),(1, 2, 3)]`

योग
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उत्तर

A = `[(5, 3, 8),(2, 0, 1),(1, 2, 3)]`

Cofactr of 2, A21 = `(- 1)^(2 + 1)  |(3, 8),(2, 3)|`

= – [9 – 16]

= 7

Cofactr of 0, A22 = `(- 1)^(2 + 2)  |(5, 8),(1, 3)|`

= 15 – 8

= 7

Cofactr of 1, A23 = `(- 1)^(2 + 3)  |(5, 3),(1, 2)|`

= – [10 – 3]

= – 7

∴ |A| = a21 A21 + a22 A22 + a23 A23

= 2 × 7 + 0 × 7 + 1 × – 7

= 14 – 7

|A| = 7

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Determinants
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 7: Matrices and Determinants - Exercise 7.2 [पृष्ठ ३०]

APPEARS IN

सामाचीर कलवी Mathematics - Volume 1 and 2 [English] Class 11 TN Board
अध्याय 7 Matrices and Determinants
Exercise 7.2 | Q 21 | पृष्ठ ३०

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