About this article
Published Online: Dec 30, 2015
Page range: 69 - 79
Received: Apr 10, 2015
DOI: https://doi.org/10.1515/aupcsm-2015-0006
Keywords
© by Renata Malejki
This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.
We prove some stability and hyperstability results for a generalization of the well known Fréchet functional equation, stemming from one of the characterizations of the inner product spaces. As the main tool we use a fixed point theorem for some function spaces. We end the paper with some new inequalities characterizing the inner product spaces.