International Journal of Mathematics and Mathematical Sciences 
Volume 27 (2001), Issue 5, Pages 301-307
doi:10.1155/S0161171201005348

A functional equation characterizing cubic polynomials and its stability

Soon-Mo Jung1 and Prasanna K. Sahoo2

1Mathematics Section, College of Science & Technology, Hong–Ik University, Chochiwon 339–701, Korea
2Department of Mathematics, University of Louisville, Louisville 40292, KY, USA

Received 30 May 2000

Abstract

We study the generalized Hyers-Ulam stability of the functional equation f[x1,x2,x3]=h(x1+x2+x3).