##### Lecture on Co-factor
Content covered:

Cofactor of an element in a determinant

A = $\begin{vmatrix}a11&a12&a13\\a21&a22&a23\\a31&a32&a33\end{vmatrix} aij=Mij*(-1)^(i+j)$

$​cf(a32)=A32=M32*(-1)^(3+2)$

$-1* \begin{vmatrix}a11&a13\\a21&a23\end{vmatrix}$

Sum of product of elements of rows with its corresponding cofactors = value of determinant