바로가기메뉴

본문 바로가기 주메뉴 바로가기

logo

  • P-ISSN3059-0604
  • E-ISSN3059-1309
  • KCI

HYERS-ULAM STABILITY OF AN ADDITIVE (ρ1, ρ2)-FUNCTIONAL INEQUALITY IN BANACH SPACES

Journal of the Korean Society of Mathematical Education Series B: Theoretical Mathematics and Pedagogical Mathematics / Journal of the Korean Society of Mathematical Education Series B: Theoretical Mathematics and Pedagogical Mathematics, (P)3059-0604; (E)3059-1309
2018, v.25 no.2, pp.161-170
https://doi.org/10.7468/jksmeb.2018.25.2.161
Park, Choonkil
Yun, Sungsik

Abstract

In this paper, we introduce and solve the following additive (<TEX>${\rho}_1,{\rho}_2$</TEX>)-functional inequality (0.1) <TEX>f(x+y+z)f(x)f(y)f(z)ρ1(f(x+z)f(x)f(z))+ρ2(f(y+z)f(y)f(z))

</TEX>, where <TEX>${\rho}_1$</TEX> and <TEX>${\rho}_2$</TEX> are fixed nonzero complex numbers with <TEX>${\mid}{\rho}_1{\mid}+{\mid}{\rho}_2{\mid}$</TEX> < 2. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the additive (<TEX>${\rho}_1,{\rho}_2$</TEX>)-functional inequality (0.1) in complex Banach spaces.

keywords
Hyers-Ulam stability, additive (<tex> ${\rho}_1, {\rho}_2$</tex>)-functional inequality, fixed point method, direct method, Banach space

Journal of the Korean Society of Mathematical Education Series B: Theoretical Mathematics and Pedagogical Mathematics