If Δ=|a11a12a13a21a22a23a31a32a33| and Aij is the cofactor of aij, then the value of Δ is given by:
(4)
Ans. a11A11+a21A21+a31A31
Explanation:
∆= sum of the products of the elements of any row (or any column) with their corresponding cofactors.
∴ Δ=a11A11+a21A21+a31A31