Results 41 to 50 of about 89 (80)

New Results about Quadratic Functional Equation on Semigroups

Annales Mathematicae Silesianae
Let S be a semigroup, let (H, +) be a uniquely 2-divisible, abelian group and let φ, ψ be two endomorphisms of S that need not be involutive. In this paper, we express the solutions f : S → H of the following quadratic functional equation f(xφ(y))+f(ψ(y)
Akkaoui Ahmed, Fadli Brahim
doaj   +1 more source

Derivation Pairs on Rings and RNGs

Annales Mathematicae Silesianae
We generalize a classical result about derivation pairs on function algebras. Specifically, we describe the forms of derivation pairs on rings and rngs (non-unital rings) which are not assumed to be commutative.
Ebanks Bruce
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Stability of an additive-quadratic functional equation in modular spaces

Open Mathematics
Using 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, Rossafi Mohamed, Park Choonkil, Donganont Mana   +3 more
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Inverse Ambiguous Functions and Automorphisms on Finite Groups

Annales Mathematicae Silesianae, 2019
If G is a finite group, then a bijective function f : G → G is inverse ambiguous if and only if f(x)−1 = f−1(x) for all x ∈ G. We give a precise description when a finite group admits an inverse ambiguous function and when a finite group admits an ...
Toborg Imke
doaj   +1 more source

Stability and hyperstability of a quadratic functional equation and a characterization of inner product spaces

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, El-Fassi Iz-iddine, Park Choonkil   +2 more
doaj   +1 more source

A Pexiderized Cosine Functional Equation

Annales Mathematicae Silesianae
Let S be a semigroup and K be a field. In a recent article we introduced a new cosine functional equation g(xyz) − g(x)g(yz) − g(y)g(xz) − g(z)g(xy) + 2g(x)g(y)g(z) = 0 for an unknown function g : S → K.
Ebanks Bruce
doaj   +1 more source

On Almost Everywhere K-Additive Set-Valued Maps

Annales Mathematicae Silesianae
Let 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 Silesianae
We 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
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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, Sintunavarat Wutiphol   +1 more
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On Functions with Monotonic Differences

Annales Mathematicae Silesianae
Motivated 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