Department of Mathematics, Semnan University, P.O. Box 35195-363, Semnan, Iran
Academic Editor: John M. Rassias
Copyright © 2010 M. Bidkham 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 prove the Hyers-Ulam stability of the polynomial equation . We give an affirmative answer to a problem posed by Li and Hua (2009).