Non-Archimedean stability of an AQQ functional equation

Abstract

Recently, Mohammadi et al. [24] proved the Hyers-Ulam stability of the following additive-quadratic-quartic functional equation f (x + 2y) + f (x - 2y) = 2f (x + y) + 2f (-x - y) + 21 (x - y) + 2f (y - x) - 4f (-x) - 2f (x) + f (2y) + f (-2y) - 4f (y) - 4f (-y) in random normed spaces. In this paper, we prove the Hyers-Ulam stability of the above functional equation in non-Archimedean normed spaces.