Wan Xin Xu

A Fixed Point Approach to the Stability of Quintic and Sextic Functional Equations in Quasi--Normed Spaces

We achieve the general solution of the quintic functional equation and the sextic functional equation . Moreover, we prove the stability of the quintic and sextic functional equations in quasi--normed spaces via fixed point method.

Intuitionistic fuzzy stability of a general mixed additive-cubic equation

We establish some stability results concerning the general mixed additive-cubic functional equation, f(kx+y)+f(kx−y)=kf(x+y)+kf(x−y)+2f(kx)−2kf(x),in intuitionistic fuzzy normed spaces. In addition, we show under some suitable conditions that an approximately mixed additive-cubic function can be approximated by a mixed additive and cubic mapping.

Stability of a general mixed additive-cubic functional equation in non-Archimedean fuzzy normed spaces

We establish some stability results concerning the general mixed additive-cubic functional equation in non-Archimedean fuzzy normed spaces. In addition, we establish some results of approximately general mixed additive-cubic mappings in non-Archimedean fuzzy normed spaces. The results improve and extend some recent results.

A Fixed Point Approach to the Stability of a General Mixed AQCQ-Functional Equation in Non-Archimedean Normed Spaces

Using the fixed point methods, we prove the generalized Hyers-Ulam stability of the general mixed additive-quadratic-cubic-quartic functional equation 𝑓(𝑥

On the Stability of a General Mixed Additive-Cubic Functional Equation in Random Normed Spaces

We prove the generalized Hyers-Ulam stability of the following additive-cubic equation in the setting of random normed spaces.

Stability of quintic and sextic functional equations in non-archimedean fuzzy normed spaces

We use the fixed point method to study the Hyers-Ulam stability of the quintic and sextic functional equations in non-Archimedean fuzzy normed spaces. In addition, we establish some results of approximately quintic and sextic mappings in non-Archimedean fuzzy normed spaces. Some applications of our result will be illustrated.