Zobrazeno 1 - 10
of 17
pro vyhledávání: '"Chang-Kwon Choi"'
Publikováno v:
Journal of Function Spaces, Vol 2015 (2015)
Let S and G be a commutative semigroup and a commutative group, respectively, C and R+ the sets of complex numbers and nonnegative real numbers, respectively, and σ:S→S or σ:G→G an involution. In this paper, we first investigate general solutio
Externí odkaz:
https://doaj.org/article/11c8c1b101cb43ad9fcbd512573951ba
Autor:
Chang-Kwon Choi
Publikováno v:
Indagationes Mathematicae. 30:240-249
Let X be a real normed vector space and f : ( 0 , ∞ ) → X . In this paper, we prove the hyperstability of the logarithmic functional equation f x y − y f ( x ) = 0 on Γ of Lebesgue measure zero. More precisely, we prove that if f : ( 0 , ∞ )
Autor:
Chang-Kwon Choi, Bogeun Lee
Publikováno v:
Results in Mathematics. 75
In this paper, using the Baire category theorem we investigate the Hyers–Ulam stability problem of mixed additive–quadratic and additive–Drygas functional equations $$\begin{aligned} 2f(x+y) + f(x-y) - 3f(x) -3f(y)&= 0,\\ 2f(x+y) + f(x-y) - 3f(
Autor:
Chang-Kwon Choi
Publikováno v:
Bulletin of the Australian Mathematical Society. 97:471-479
Let $N$ be a fixed positive integer and $f:\mathbb{R}\rightarrow \mathbb{C}$. As a generalisation of the superstability of the exponential functional equation we consider the functional inequalities $$\begin{eqnarray}\displaystyle & \displaystyle \bi
Autor:
Chang-Kwon Choi
Publikováno v:
Results in Mathematics. 72:2067-2077
Let X and Y be Banach spaces and $$f\,{:}\,X \rightarrow Y$$ . Generalizing the result of Gilanyi (Proc Natl Acad Sci USA 96:10588–10590, 1999) we study the Hyers–Ulam stability problem of the monomial functional equation $$\begin{aligned} \Delta
Publikováno v:
Ann. Funct. Anal. 8, no. 3 (2017), 329-340
In this paper, we consider the Ulam–Hyers stability of the functional equations \[f(ux-vy,uy-vx)=f(x,y)f(u,v),\] \[f(ux+vy,uy-vx)=f(x,y)f(u,v),\] \[f(ux+vy,uy+vx)=f(x,y)f(u,v),\] \[f(ux-vy,uy+vx)=f(x,y)f(u,v)\] for all $x,y,u,v\in\Bbb{R}$ , where $
Publikováno v:
Canadian Mathematical Bulletin. 60:95-103
Let X be a real normed space, Y a Banach space, and f : X → Y. We prove theUlam–Hyers stability theorem for the cubic functional equationin restricted domains. As an application we consider a measure zero stability problem of the inequalityfor al
Publikováno v:
Far East Journal of Mathematical Sciences (FJMS). 101:569-581
Publikováno v:
Bulletin of the Australian Mathematical Society. 95:260-268
We find all real-valued general solutions$f:S\rightarrow \mathbb{R}$of the d’Alembert functional equation with involution$$\begin{eqnarray}\displaystyle f(x+y)+f(x+\unicode[STIX]{x1D70E}y)=2f(x)f(y) & & \displaystyle \nonumber\end{eqnarray}$$for al
Publikováno v:
Frontiers in Functional Equations and Analytic Inequalities ISBN: 9783030289492
Let X, Y be real Banach spaces, f : X → Y and \(\mathcal H\) be a subset of X such that \({\mathcal H}^c\) is of the first category. Using the Baire category theorem we prove the Ulam–Hyers stability of the linear functional equation
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e9e5def49e944a2815e6d3473ce37832
https://doi.org/10.1007/978-3-030-28950-8_2
https://doi.org/10.1007/978-3-030-28950-8_2