#### Question

Using Cofactors of elements of second row, evaluate `triangle = |(5,3,8),(2,0,1),(1,2, 3)|`

#### Solution

The given determinant is ` |(5,3,8),(2,0,1),(1,2, 3)|`

We have:

∴A_{23 }= cofactor of *a*_{23 }= (−1)^{2+3} M_{23} = −7

We know that Δ is equal to the sum of the product of the elements of the second row with their corresponding cofactors.

∴Δ = *a*_{21}A_{21} + *a*_{22}A_{22} + *a*_{23}A_{23} = 2(7) + 0(7) + 1(−7) = 14 − 7 = 7

Is there an error in this question or solution?

Solution Using Cofactors of Elements of Second Row, Evaluate Triangle = |(5,3,8),(2,0,1),(1,2, 3)| Concept: Minors and Co-factors.