On the superstability of the cosine and sine type functional equations

Fouad Lehlou, et al. "On the superstability of the cosine and sine type functional equations." Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica 15 (2016): 113-121. <http://eudml.org/doc/287081>.

@article{FouadLehlou2016,
abstract = {In this paper, we study the superstablity problem of the cosine and sine type functional equations: f(xσ(y)a)+f(xya)=2f(x)f(y) \[f(x\sigma (y)a) + f(xya) = 2f(x)f(y)\] and f(xσ(y)a)−f(xya)=2f(x)f(y), \[f(x\sigma (y)a) - f(xya) = 2f(x)f(y),\] where f : S → ℂ is a complex valued function; S is a semigroup; σ is an involution of S and a is a fixed element in the center of S.},
author = {Fouad Lehlou, Mohammed Moussa, Ahmed Roukbi, Samir Kabbaj},
journal = {Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica},
keywords = {functional equation; superstablity; stablity; cosine functional equation; sine functional equation},
language = {eng},
pages = {113-121},
title = {On the superstability of the cosine and sine type functional equations},
url = {http://eudml.org/doc/287081},
volume = {15},
year = {2016},
}

TY - JOUR
AU - Fouad Lehlou
AU - Mohammed Moussa
AU - Ahmed Roukbi
AU - Samir Kabbaj
TI - On the superstability of the cosine and sine type functional equations
JO - Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica
PY - 2016
VL - 15
SP - 113
EP - 121
AB - In this paper, we study the superstablity problem of the cosine and sine type functional equations: f(xσ(y)a)+f(xya)=2f(x)f(y) \[f(x\sigma (y)a) + f(xya) = 2f(x)f(y)\] and f(xσ(y)a)−f(xya)=2f(x)f(y), \[f(x\sigma (y)a) - f(xya) = 2f(x)f(y),\] where f : S → ℂ is a complex valued function; S is a semigroup; σ is an involution of S and a is a fixed element in the center of S.
LA - eng
KW - functional equation; superstablity; stablity; cosine functional equation; sine functional equation
UR - http://eudml.org/doc/287081
ER -