Question

If `Delta=|a_(11)a_(12)a_(13)a_(21)a_(22)a_(23)a_(31)a_(32)a_(33)|` and `A_(i j)` is cofactors of `a_(i j)` , then value of `Delta` is given by (A) `a_(11)+A_(31)+a_(12)A_(32)+a_(13)A_(33)` (B) `a_(11)A_(11)+a_(12)A_(21)+a_(13)A_(31)` (C) `a_(21)A

Answer 1

Correct Answer - (d)
The value o a determinant is equal to the sum of the product of the elements of a row or columen and their corresponding cofactors.
`Delta=a_(11)A_(11)++a_(21)A_(21)+a_(31)A_(31)`