In this paper we first introduce a new concept of a functional
equation called multi-Drygas equation. We deal with the generalized hyperstability
results of the multi-Drygas functional equation on a restricted
domain by applying the Brzd¸ek’s fixed point theorem (Brzd¸ek et al. in
Nonlinear Anal. 74: 6728–6732, 2011, Theorem 1). Our main results improve
and generalize results obtained in Aiemsombonn and Sintunavarat
(Bull Aust Math Soc 92: 269–280, 2016), El-Fassi(J Fixed Point Theory
Appl 9: 2529–2540, 2017), Piszczek, Szczawi´nska(J Funct Spaces Appl
2013: 912718, 2013) . Some applications of our results are also provided.
