The first practical application that comes to mind should be handling of matrix equations and solving of a system of linear equations, see here. ... <看更多>

You can try using the Moore-Penrose inverse of a matrix, which always exists. But be aware that in case of non-invertible matrices, ... ... <看更多>

Let A be an n by n matrix. Then rank(A) = n iff A has an inverse. ... <看更多>