A FIXED POINT APPROACH TO THE INTUITIONISTIC FUZZY STABILITY OF QUINTIC AND SEXTIC FUNCTIONAL EQUATIONS
نویسندگان
1 Department of Statistical, University College London, Science 1-19 Torrington Place, London WC1E 7HB, United Kingdom
2 Department of Electrical and Computer Engineering, College of En- gineering, University of Kentucky, Lexington 40506, Usa and School of Communica- tion and Information Engineering, University of Electronic Science and Technology of China
3 School of Mathematics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
doi
10.22111/ijfs.2012.102چکیده
The fixed point alternative methods are implemented to giveHyers-Ulam stability for the quintic functional equation $ f(x+3y)- 5f(x+2y) + 10 f(x+y)- 10f(x)+ 5f(x-y) - f(x-2y) = 120f(y)$ and thesextic functional equation $f(x+3y) - 6f(x+2y) + 15 f(x+y)- 20f(x)+15f(x-y) - 6f(x-2y)+f(x-3y) = 720f(y)$ in the setting ofintuitionistic fuzzy normed spaces (IFN-spaces). This methodintroduces a metrical context and shows that the stability isrelated to some fixed point of a suitable operator. Furthermore, theinterdisciplinary relation among the fuzzy set theory, the theoryof intuitionistic spaces and the theory of functional equations arealso presented in the paper.
