Sylvester's determinant identity
Not to be confused with the Weinstein–Aronszajn identity, which is sometimes attributed to Sylvester.
In matrix theory, Sylvester's determinant identity is an identity useful for evaluating certain types of determinants. It is named after James Joseph Sylvester, who stated this identity without proof in 1851.
Given an n-by-n matrix, let denote its determinant. Choose a pair
of m-element ordered subsets of, where m ≤ n.
Let denote the -by- submatrix of obtained by deleting the rows in and the columns in.
Define the auxiliary m-by-m matrix whose elements are equal to the following determinants
where, denote the m−1 element subsets of and obtained by deleting the elements and, respectively. Then the following is Sylvester's determinantal identity :
When m = 2, this is the Desnanot-Jacobi identity.
