Title of article :
A new type of Hyers-Ulam-Rassias stability for Drygas functional equation
Author/Authors :
Sirouni, M. Department of Mathematics - Faculty of Science - Ibn Tofail University, Morocco , Almahalebi, M. Department of Mathematics - Faculty of Science - Ibn Tofail University, Morocco , Kabbaj, S. Department of Mathematics - Faculty of Science - Ibn Tofail University, Morocco
Abstract :
this paper, we prove the generalized Hyers-Ulam-Rassias stability for the Dry- gas functional equation
f(x + y) + f(x _ y) = 2f(x) + f(y) + f( _ y)
in Banach spaces by using the Brzdek's xed point theorem. Moreover, we give a general result on the hyperstability of this equation. Our results are improvements and generalizations of the main result of M. Piszczek and J. Szczawinska [21].
Keywords :
Stability , hyperstability , Drygas functional equation , xed point method , Banach space
Journal title :
Astroparticle Physics
