Inverse matrix: Let A be an n-order square matrix in a number field. If there exists another n-order matrix B in the same number field, such that: AB=BA=E. Then we call B the inverse matrix of A, and A is called a reversible matrix.

In linear algebra, the adjoint matrix of a square matrix is ​​a concept similar to the inverse matrix. If the matrix is ​​invertible, then its inverse matrix and its adjoint matrix differ by only one coefficient. However, the adjoint matrix is ​​also defined for non-invertible matrices, and does not require division.

In mathematics, a determinant is a formula generated by solving a system of linear equations. The characteristics of a determinant can be summarized as a multiple alternating linear form, which makes the determinant a function that describes "volume" in Euclidean space.