20211108 det(AB)=det(A)det(B)

For two square matrices with equal dimensions $A$ and $B$,
$$det(AB)=det(A)det(B)=det(BA)$$

$det$ Represents the product of eigenvalues of a matrix , in other words $A$ All the eigenvalues of ,$B$ All eigenvalues of are multiplied , be equal to $AB$ Product of all eigenvalues of , Also equal to $BA$ Product of all eigenvalues of .