ADDITIVE-QUADRATIC ρ-FUNCTIONAL INEQUALITIES IN FUZZY NORMED SPACES
ADDITIVE-QUADRATIC ρ-FUNCTIONAL INEQUALITIES IN FUZZY NORMED SPACES
한국수학교육학회지시리즈B:순수및응용수학 / Journal of the Korean Society of Mathematical Education Series B: The Pure and Applied Mathematics, (P)1226-0657; (E)2287-6081
2016, v.23 no.3, pp.247-263
https://doi.org/10.7468/jksmeb.2016.23.3.247
YUN, SUNGSIK
(DEPARTMENT OF FINANCIAL MATHEMATICS, HANSHIN UNIVERSITY)
LEE, JUNG RYE
(DEPARTMENT OF MATHEMATICS, DAEJIN UNIVERSITY)
SHIN, DONG YUN
(DEPARTMENT OF MATHEMATICS, UNIVERSITY OF SEOUL)
YUN, SUNGSIK,
LEE, JUNG RYE,
&
SHIN, DONG YUN.
(2016). ADDITIVE-QUADRATIC ρ-FUNCTIONAL INEQUALITIES IN FUZZY NORMED SPACES. 한국수학교육학회지시리즈B:순수및응용수학, 23(3), 247-263, https://doi.org/10.7468/jksmeb.2016.23.3.247
Abstract
Let <TEX>$M_{1}f(x,y):=\frac{3}{4}f(x+y)-\frac{1}{4}f(-x-y)+\frac{1}{4}f(x-y)+\frac{1}{4}f(y-x)-f(x)-f(y)$</TEX>, <TEX>$M_{2}f(x,y):=2f(\frac{x+y}{2})+f(\frac{x-y}{2})+f(\frac{y-x}{2})-f(x)-f(y)$</TEX>. Using the direct method, we prove the Hyers-Ulam stability of the additive-quadratic ρ-functional inequalities (0.1) <TEX>$N(M_{1}f(x,y),t){\geq}N({\rho}M_{2}f(x,y),t)$</TEX> where ρ is a fixed real number with |ρ| < 1, and (0.2) <TEX>$N(M_{2}f(x,y),t){\geq}N({\rho}M_{1}f(x,y),t)$</TEX> where ρ is a fixed real number with |ρ| < <TEX>$\frac{1}{2}$</TEX>.
- keywords
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fuzzy Banach space,
additive-quadratic ρ-functional inequality,
Hyers-Ulam stability