Journal of Inequalities and Applications
Volume 2009 (2009), Article ID 976284, 10 pages
doi:10.1155/2009/976284
Research Article

Stability of a Bi-Jensen Functional Equation II

Kil-Woung Jun,1 Il-Sook Jung,1 and Yang-Hi Lee2

1Department of Mathematics, Chungnam National University, Daejeon 305-764, South Korea
2Department of Mathematics Education, Gongju National University of Education, Gongju 314-711, South Korea

Received 7 October 2008; Accepted 24 January 2009

Academic Editor: Alexander Domoshnitsky

Copyright © 2009 Kil-Woung Jun 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.

Abstract

We investigate the stability of the bi-Jensen functional equation II f((x+y)/2,z)−f(x,z)−f(y,z)=0,  2f(x,(y+z)/2)−f(x,y)−f(x,z)=0 in the spirit of Găvruta.