Copyright © 2011 Yu-Ming Chu 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
For p∈[0,1], the generalized Seiffert mean of two positive numbers a and b is defined by Sp(a,b)=p(a-b)/arctan[2p(a-b)/(a+b)], 0<p≤1, a≠b; (a+b)/2, p=0, a≠b; a, a=b. In this paper, we find the greatest value α and least value β such that the double inequality Sα(a,b)<T(a,b)<Sβ(a,b) holds for all a,b>0 with a≠b, and give new bounds for the complete elliptic integrals of the second kind. Here, T(a,b)=(2/π)∫0π/2a2cos2θ+b2sin2θdθ denotes the Toader mean of two positive numbers a and b.