Fixed Point Theory and Applications
Volume 2005 (2005), Issue 3, Pages 321-342
doi:10.1155/FPTA.2005.321
    
    
    Existence of extremal solutions for quadratic fuzzy equations
    
    Departamento de Análisis Matemático, Facultad de Matemáticas, Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain
    
    
    
    Received 8 November 2004; Revised 8 March 2005
    	
    
     
    Copyright © 2005 Juan J. Nieto and Rosana Rodríguez-López. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
     
    
   
 
Abstract
Some results on the existence of solution for certain fuzzy equations are revised and extended. In this paper, we establish the existence of a solution for the fuzzy equation Ex2+Fx+G=x, where E, F, G, and x are positive fuzzy numbers satisfying certain conditions. To this purpose, we use fixed point theory, applying results such as  the well-known fixed point theorem of Tarski, presenting some results regarding the existence of extremal solutions to the above equation.