On the Stability of Quadratic Functional Equations

Let X,Y be vector spaces and k a fixed positive integer. It is shown that a mapping f(kx+y)+f(kx-y)=2k2f(x)+2f(y) for all x,y∈X if and only if the mapping f:X→Y satisfies f(x+y)+f(x-y)=2f(x)+2f(y) for all x,y∈X. Furthermore, the Hyers-Ulam-Rassias stability of the above functional equation in Banac...

Full description

Saved in:
Bibliographic Details
Main Authors: Jung Rye Lee, Jong Su An, Choonkil Park
Format: Article
Language:English
Published: Wiley 2008-01-01
Series:Abstract and Applied Analysis
Online Access:http://dx.doi.org/10.1155/2008/628178
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832567085318799360
author Jung Rye Lee
Jong Su An
Choonkil Park
author_facet Jung Rye Lee
Jong Su An
Choonkil Park
author_sort Jung Rye Lee
collection DOAJ
description Let X,Y be vector spaces and k a fixed positive integer. It is shown that a mapping f(kx+y)+f(kx-y)=2k2f(x)+2f(y) for all x,y∈X if and only if the mapping f:X→Y satisfies f(x+y)+f(x-y)=2f(x)+2f(y) for all x,y∈X. Furthermore, the Hyers-Ulam-Rassias stability of the above functional equation in Banach spaces is proven.
format Article
id doaj-art-2c305513ce404e5ab3928f0821248895
institution Kabale University
issn 1085-3375
1687-0409
language English
publishDate 2008-01-01
publisher Wiley
record_format Article
series Abstract and Applied Analysis
spelling doaj-art-2c305513ce404e5ab3928f08212488952025-02-03T01:02:19ZengWileyAbstract and Applied Analysis1085-33751687-04092008-01-01200810.1155/2008/628178628178On the Stability of Quadratic Functional EquationsJung Rye Lee0Jong Su An1Choonkil Park2Department of Mathematics, Daejin University, Kyeonggi 487-711, South KoreaDepartment of Mathematics Education, Pusan National University, Pusan 609-735, South KoreaDepartment of Mathematics, Hanyang University, Seoul 133-791, South KoreaLet X,Y be vector spaces and k a fixed positive integer. It is shown that a mapping f(kx+y)+f(kx-y)=2k2f(x)+2f(y) for all x,y∈X if and only if the mapping f:X→Y satisfies f(x+y)+f(x-y)=2f(x)+2f(y) for all x,y∈X. Furthermore, the Hyers-Ulam-Rassias stability of the above functional equation in Banach spaces is proven.http://dx.doi.org/10.1155/2008/628178
spellingShingle Jung Rye Lee
Jong Su An
Choonkil Park
On the Stability of Quadratic Functional Equations
Abstract and Applied Analysis
title On the Stability of Quadratic Functional Equations
title_full On the Stability of Quadratic Functional Equations
title_fullStr On the Stability of Quadratic Functional Equations
title_full_unstemmed On the Stability of Quadratic Functional Equations
title_short On the Stability of Quadratic Functional Equations
title_sort on the stability of quadratic functional equations
url http://dx.doi.org/10.1155/2008/628178
work_keys_str_mv AT jungryelee onthestabilityofquadraticfunctionalequations
AT jongsuan onthestabilityofquadraticfunctionalequations
AT choonkilpark onthestabilityofquadraticfunctionalequations