• 충청수학회지
• /
• 제36권2호
• /
• pp.107-123
• /
• 2023

In this paper, we present some hyperstability results for a general quintic functional equation and a general septic functional equation.

• Nonlinear Functional Analysis and Applications
• /
• 제28권3호
• /
• pp.671-684
• /
• 2023

In this paper, we prove the generalized Hyers-Ulam stability of a general quintic functional equation, $\sum\limits_{k=0}^{6}(-1)^k{_6}C_kf(x+(3-k)y)=0$, by using the fixed point method.

• 충청수학회지
• /
• 제34권3호
• /
• pp.295-306
• /
• 2021

The general sextic functional equation is a generalization of many functional equations such as the additive functional equation, the quadratic functional equation, the cubic functional equation, the quartic functional equation and the quintic functional equation. In this paper, motivating the method of Găvruta [J. Math. Anal. Appl., 184 (1994), 431-436], we will investigate the stability of the general sextic functional equation.

• 충청수학회지
• /
• 제26권4호
• /
• pp.757-767
• /
• 2013

We investigate the general solution of the following functional equation and the generalized Hyers-Ulam-Rassias stability problem in quasi ${\beta}$-normed spaces and then the stability by using alternative fixed point method for the following quintic function $f:X{\rightarrow}Y$ such that f(3x+y)+f(3x-y)+5[f(x+y)+f(x-y)]=4[f(2x+y)+f(2x-y)]+2f(3x)-246f(x), for all $x,y{\in}X$.