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A special class of functional equations

  • Ahmed Charifi EMAIL logo , Radosław Łukasik and Driss Zeglami
Published/Copyright: March 31, 2018
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Abstract

We obtain in terms of additive and multi-additive functions the solutions f, h: SH of the functional equation

λΦf(x+λy+aλ)=Nf(x)+h(y),x,yS,

where (S, +) is an abelian monoid, Φ is a finite group of automorphisms of S, N = | Φ | designates the number of its elements, {aλ, λ ∈ Φ} are arbitrary elements of S and (H, +) is an abelian group. In addition, some applications are given. This equation provides a joint generalization of many functional equations such as Cauchy’s, Jensen’s, Łukasik’s, quadratic or Φ-quadratic equations.

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Received: 2015-10-5
Accepted: 2016-8-25
Published Online: 2018-3-31
Published in Print: 2018-4-25

© 2018 Mathematical Institute Slovak Academy of Sciences

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