Copyright © 2009 Hongjian Xi et al. 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
We study the boundedness of the
difference equation xn+1=(pxn+qxn−1)/(1+xn), n=0,1,…, where q>1+p>1 and the initial values x−1,x0∈(0,+∞). We show that the solution
{xn}n=−1∞ of this equation converges to
x¯=q+p−1 if xn≥x¯ or xn≤x¯ for all
n≥−1; otherwise {xn}n=−1∞ is unbounded. Besides, we obtain the set of all initial values (x−1,x0)∈(0,+∞)×(0,+∞) such that the positive solutions
{xn}n=−1∞ of this equation are bounded, which
answers the open problem 6.10.12 proposed by Kulenović and Ladas (2002).