Results 61 to 70 of about 502 (93)
Stability of an additive-quadratic functional equation in modular spaces
Open MathematicsUsing the direct method, we prove the Hyers-Ulam-Rassias stability of the following functional equation: ϕ(x+y,z+w)+ϕ(x−y,z−w)−2ϕ(x,z)−2ϕ(x,w)=0\phi \left(x+y,z+w)+\phi \left(x-y,z-w)-2\phi \left(x,z)-2\phi \left(x,w)=0 in ρ\rho -complete convex modular ...
Baza Abderrahman +3 more
doaj +1 more source
Demonstratio Mathematica, 2018 We have proved theHyers-Ulam stability and the hyperstability of the quadratic functional equation f (x + y + z) + f (x + y − z) + f (x − y + z) + f (−x + y + z) = 4[f (x) + f (y) + f (z)] in the class of functions from an abelian group G into a Banach ...
Kim Gwang Hui +2 more
doaj +1 more source
Intuitionistic fuzzy almost Cauchy–Jensen mappings
Demonstratio Mathematica, 2016 In this paper, we first investigate the Hyers–Ulam stability of the generalized Cauchy–Jensen functional equation of p-variable f(∑i=1paixi)=∑i=1paif(xi)$f\left(\sum\nolimits_{i = 1}^p {a_i x_i } \right) = \sum\nolimits_{i = 1}^p {a_i f(x_i )}$ in an ...
Gordji M. E., Abbaszadeh S.
doaj +1 more source
On Almost Everywhere K-Additive Set-Valued Maps
Annales Mathematicae SilesianaeLet X be an Abelian group, Y be a commutative monoid, K ⊂Y be a submonoid and F : X → 2Y \ {∅} be a set-valued map. Under some additional assumptions on ideals ℐ1 in X and ℐ2 in X2, we prove that if F is ℐ2-almost everywhere K-additive, then there ...
Jabłońska Eliza
doaj +1 more source
Speed of Light or Composition of Velocities
Annales Mathematicae SilesianaeWe analyze in our paper questions of the theory of relativity. We approach this theory from the point of view of velocities and their composition. This is where the functional equations appear.
Sablik Maciej
doaj +1 more source
Orthogonal stability of the generalized quadratic functional equations in the sense of Rätz
Demonstratio Mathematica, 2019 Let (X, ⊥) be an orthogonality module in the sense of Rätz over a unital Banach algebra A and Y be a real Banach module over A. In this paper, we apply the alternative fixed point theorem for proving the Hyers-Ulam stability of the orthogonally ...
Aiemsomboon Laddawan +1 more
doaj +1 more source
On Functions with Monotonic Differences
Annales Mathematicae SilesianaeMotivated by the Szostok problem on functions with monotonic differences (2005, 2007), we consider a-Wright convex functions as a generalization of Wright convex functions.
Rajba Teresa
doaj +1 more source
Functional Equations with an Anti-Endomorphism for Functions with Multidimensional Codomains
Annales Mathematicae SilesianaeLet S be a semigroup, ℍ be the skew field of quaternions, and ψ: S → S be an anti-endomorphism. We determine the general solution of the functional equation g(xy)-g(xψ(y))=2g(x)g(y), x, y∈S,g\left( {xy} \right) - g\left( {x\psi \left( y \right)}
Ouhabi Ayoub +2 more
doaj +1 more source
Generalized Hyers–Ulam stability of mixed-type additive-quartic mappings in 2-Banach spaces
Demonstratio MathematicaThis paper aims to explore the stability of a mixed-type additive-quartic functional equation in 2-Banach spaces via the direct method. We categorize mappings satisfying a certain functional inequality into odd, even, and general mappings, and establish ...
Ponmana Selvan Arumugam +2 more
doaj +1 more source
On the Ulam-Hyers stability of a quadratic functional equation
Journal of Inequalities and Applications, 2011 The Ulam-Hyers stability problems of the following quadratic equation r 2 f x + y r + r 2 f x - y r = 2 f ( x ) + 2 f ( y ) , where r is a nonzero rational number, shall be treated.
Park Won-Gil +2 more
doaj