Stability of a functional equation deriving from quartic and additive functions

A fixed point approach to the stability of additive-quadratic-quartic functional equations

In this article, we introduce a class of the generalized mixed additive, quadratic and quartic functional equations and obtain their common solutions. We also investigate the stability of such modified functional equations in the non-Archimedean normed spaces by a fixed point method.

Intuitionistic fuzzy stability of a quadratic and quartic functional equation

In this paper, we prove the generalized Hyers--Ulamstability of a quadratic and quartic functional equation inintuitionistic fuzzy Banach spaces.

On the Stability of the Orthogonally Quartic Functional Equation

Stability of a Functional Equation Deriving from Cubic and Quartic Functions

In this paper, we obtain the general solution and the generalized Ulam-Hyers stability of the cubic and quartic functional equation 4(f(3x + y) + f(3x− y)) = −12(f(x + y) + f(x− y)) + 12(f(2x + y) + f(2x− y))− 8f(y)− 192f(x) + f(2y) + 30f(2x).

Cubic-quartic functional equations in fuzzy normed spaces

In this paper, we investigate the generalizedHyers--Ulam stability of the functional equation