Academic Editor: Patricia J. Y. Wong
Copyright © 2010 In Goo Cho et al. This is an open access article distributed under the
Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
We investigate the generalized Hyers-Ulam-Rassias stability problem
in quasi--normed spaces and then the stability by using a subadditive
function for the quintic function such that , for all .