If Δ=|a h g h b f g f c|, then the cofactor A21 is

Question

If Δ=|a h g h b f g f c|, then the cofactor A21 is (A) -(h c+f g) (B) f g-h c (C) f g+h c (D) h c-f g

Tardigrade Admin · Accepted Answer

We have, Δ=|a h g h b f g f c| Now, minor of a21 is M21=|h g f c|=h c-f g ∴ A21=(-1)2+1 M21=-(h c-f g)=f g-h c

Q. If $Δ = ∣ ∣ a h g h b f g f c ∣ ∣$ , then the cofactor $A_{21}$ is