A Pexider system of additive functional equations in Banach algebras

Abstract

Abstract In this paper, we solve the system of functional equations { f ( x + y ) + g ( y − x ) = 2 f ( x ) , g ( x + y ) − f ( y − x ) = 2 g ( y ) $$\begin{aligned} \textstyle\begin{cases} f(x+y)+g(y-x)=2f(x), \\ g(x+y)-f(y-x)=2g(y) \end{cases}\displaystyle \end{aligned}$$ and we investigate the stability of g-derivations in Banach algebras.

Keywords

• Hyers–Ulam stability
• g-derivation
• Additive mapping
• Fixed point method
• System of functional equations