Abstract: A fast algorithm for calculating the inverse and group inverse and Moore-Penrose inverse of a resultant matrix is presneted by using the fast algorithm for finding polynomials. Only the rounding error exists when the fast algorithm is realized by computers, and only the entries in the first row of the resultant matrix is used in this algorithm, so the computing results are accurate in theory.

Key words: resultant matrix, inverse matrix, group inverse, Moore-Penrose inverse, fast algorithm