the study of stability problems of functional equations was motivated by a question of s.m. ulam asked in 1940. the first result giving answer to this question is due to d.h. hyers. subsequently, his result was extended and generalized in several ways.we prove some hyperstability results for the equation g(ax+by)+g(cx+dy)=ag(x)+bg(y)on restricted domain. namely, we show, under some weak natural...

This paper is concerned with a class of implicit-type coupled system integral boundary conditions involving Caputo fractional derivatives. First, the existence result solutions for considered obtained by means topological degree theory. Next, Ulam–Hyers stability and generalized are studied under some suitable assumptions. Finally, one example worked out to illustrate main results.

The classical Gronwall inequality is one of the basic tools in theory differential and integral equations. In this paper, a new version presented extended to equations with generalized Hattaf fractional derivative involving non-singular kernel. existence uniqueness solutions for such last type are rigorously investigated. Furthermore, an application study Ulam-Hyers stability certain

* Correspondence: [email protected] Department of Mathematics Education, College of Education, Mokwon University, Daejeon, 302729, Korea Full list of author information is available at the end of the article Abstract Using the fixed-point method, we prove the generalized Hyers-Ulam stability of the functional equation f (x + y, z + w) + f (x− y, z− w) = 2f (x, z) + 2f (y,w). The quadratic for...

Let X,Y be complex vector spaces. Recently, Park and Th.M. Rassias showed that if a mapping f : X → Y satisfies f(x+ iy) + f(x− iy) = 2f(x)− 2f(y) (1) for all x, y ∈ X, then the mapping f : X → Y satisfies f(x+ y) + f(x− y) = 2f(x) + 2f(y) for all x, y ∈ X. Furthermore, they proved the generalized Hyers-Ulam stability of the functional equation (1) in complex Banach spaces. In this paper, we wi...

In this paper, by using C-class functions, we will present a coupled …xed problem in b-metric space for the single-valued operators satisfying a generalized contraction condition. First part of the paper is related to some …xed point theorems, the second part presents the uniqueness and existence for the solution of the coupled …xed point problem and in the third part we...