The probability of rectangular unimodular matrices over $\F_q[x]$
arXiv:1107.3367
Abstract
In this note, we compute the probability that a matrix can be extended to an invertible matrix over $\F_q[x]$, which turns out to be . Connections with Dirichlet's density theorem on the co-prime integers and its various generalizations are also presented.
7 pages,correct some spelling mistakes and add a remark