Hyers-Ulam stability of an n-variable quartic functional equation

Abstract

In this note we investigate the general solution for the quartic functional equation of the form $\left(n\in \mathbb{N}, \, \, n > 4 \right)$ and also investigate the Hyers-Ulam stability of the quartic functional equation in random normed spaces using the direct approach and the fixed point approach.

Keywords

• quartic functional equation
• fixed point method
• hyers-ulam stability
• random normed space
• direct method