5.101 How to find the cofactor matrix of a matrix?

Use LinearAlgebra:-Adjoint and then transpose the result. Since the Adjoint is the transpose of the cofactor.

Given

\[ \left [\begin {array}{ccc} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 10 \end {array}\right ] \]

then

restart; 
A:=Matrix([[1,2,3],[4,5,6],[7,8,10]]); 
LinearAlgebra:-Transpose(LinearAlgebra:-Adjoint(A))
 

\[ \left [\begin {array}{ccc} 2 & 2 & -3 \\ 4 & -11 & 6 \\ -3 & 6 & -3 \end {array}\right ] \]