Determinant. In mathematics, the determinant is a scalar value that is a function of the entries of a square matrix. The determinant of a matrix A is commonly denoted det (A), det A, or |A|. Its value characterizes some properties of the matrix and the linear map represented by the matrix. In particular, the determinant is nonzero if and onlyCalculator for 4x4 determinants Online Calculator for Determinant 4x4. The online calculator calculates the value of the determinant of a 4x4 matrix with the Laplace expansion in a row or column and the gaussian algorithm. Determinant 4x4. det A = | a 1 1 a 1 2 a 1 3 a 1 4 a 2 1 a 2 2 a 2 3 a 2 4 a 3 1 a 3 2 a 3 3 a 3 4 a 4 1 a 4 2 a 4 3 a 4 4 It decomposes matrix into two triangular matrices L and U such that A = L*U. L is lower triangular matrix and U is upper triangular matrix. Since A = L*U, then det(A) = det(L)*det(U). Now the fact that determinant of a triangular matrix is equal to product od elements on the diagonal allows to compute det(L) and det(U) easy.
There are a number of different ways to find the determinant of a 4 x 4 matrix, but we'll show you how to do it by using expansion along any row or column of a matrix.
A cofactor corresponds to the minor for a certain entry of the matrix's determinant. To find the cofactor of a certain entry in that determinant, follow these steps: Take the values of i and j from the subscript of the minor, Mi,j, and add them. Take the value of i + j and put it, as a power, on −1; in other words, evaluate (−1)i+j.
The first is the determinant of a product of matrices. Theorem 3.2.5: Determinant of a Product. Let A and B be two n × n matrices. Then det (AB) = det (A) det (B) In order to find the determinant of a product of matrices, we can simply take the product of the determinants. Consider the following example.