Bull. Korean Math. Soc. 2009; 46(2): 235-243
Printed March 1, 2009
https://doi.org/10.4134/BKMS.2009.46.2.235
Copyright © The Korean Mathematical Society.
Peng Cao and Bing Xu
Sichuan University
In this paper we will investigate the superstability of the generalized d'Alembert type functional equations $\sum_{i=1}^{m}f(x+\sigma^{i}(y))=kg(x)f(y)$ and $\sum_{i=1}^{m}f(x+\sigma^{i}(y))=kf(x)g(y)$.
Keywords: d'Alembert functional equation, superstability, cosine function
MSC numbers: 39B82, 39B32
2016; 53(2): 387-398
2008; 45(1): 157-167
© 2022. The Korean Mathematical Society. Powered by INFOrang Co., Ltd