You should enter the square matrix, and the calculator computes the determinant of the entered matrix.
It uses the definition of a determinant, which is a recursive calculation, and, in theory, quite resource consuming. Still, for our case, with matrixes entered manually, I believe it is enough (if not, please use Determinant by Gaussian elimination).
Determinant of a matrix
determinant of a matrix 1x1
determinant of a matrix 2x2
- determinant of a matrix nxn, where n > 2
- minor of .
Minor of - is the determinant of a (n–1) × (n–1) matrix that results from deleting the 1-th row and the j-th column of A.
That's why this is a recursive definition. For example, here is the determinant of a matrix 3x3