Aequationes mathematicae

, Volume 93, Issue 1, pp 161–203 | Cite as

On a quadratic difference assuming three values

  • Gian Luigi FortiEmail author


The aim of this work is to investigate the alternative quadratic functional equation
$$\begin{aligned} f(x+y)+f(x-y)-2f(x)-2f(y)\in \{0,1,2\}, \end{aligned}$$
where \(f{: }G \rightarrow \mathbb {R}\), G is an Abelian group, and provide a procedure for the construction of the solutions.


Quadratic equation Alternative equation Ulam–Hyers stability 

Mathematics Subject Classification

Primary 39B55 Secondary 39B82 


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Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Dipartimento di MatematicaUniversità degli Studi di MilanoMilanoItaly

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