Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic Means

For a,b>0 with a≠b, the Schwab-Borchardt mean SB(a,b) is defined as SB(a,b)={b2-a2/cos-1(a/b) if a<b,a2-b2/cosh-1(a/b) if a>b. In this paper, we find the greatest values of α1 and α2 and the least values of β1 and β2 in [0,1/2] such that H(α1a+(1-α1)b...

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Main Authors: Zai-Yin He, Yu-Ming Chu, Miao-Kun Wang
Format: Article
Language:English
Published: Wiley 2013-01-01
Series:Journal of Applied Mathematics
Online Access:http://dx.doi.org/10.1155/2013/807623
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author Zai-Yin He
Yu-Ming Chu
Miao-Kun Wang
author_facet Zai-Yin He
Yu-Ming Chu
Miao-Kun Wang
author_sort Zai-Yin He
collection DOAJ
description For a,b>0 with a≠b, the Schwab-Borchardt mean SB(a,b) is defined as SB(a,b)={b2-a2/cos-1(a/b) if a<b,a2-b2/cosh-1(a/b) if a>b. In this paper, we find the greatest values of α1 and α2 and the least values of β1 and β2 in [0,1/2] such that H(α1a+(1-α1)b,α1b+(1-α1)a)<SAH(a,b)<H(β1a+(1-β1)b,β1b+(1-β1)a) and H(α2a+(1-α2)b,α2b+(1-α2)a)<SHA(a,b)<H(β2a+(1-β2)b,β2b+(1-β2)a). Similarly, we also find the greatest values of α3 and α4 and the least values of β3 and β4 in [1/2,1] such that C(α3a+(1-α3)b,α3b+(1-α3)a)<SCA(a,b)<C(β3a+(1-β3)b,β3b+(1-β3)a) and C(α4a+(1-α4)b,α4b+(1-α4)a)<SAC(a,b)<C(β4a+(1-β4)b,β4b+(1-β4)a). Here, H(a,b)=2ab/(a+b), A(a,b)=(a+b)/2, and C(a,b)=(a2+b2)/(a+b) are the harmonic, arithmetic, and contraharmonic means, respectively, and SHA(a,b)=SB(H,A), SAH(a,b)=SB(A,H), SCA(a,b)=SB(C,A), and SAC(a,b)=SB(A,C) are four Neuman means derived from the Schwab-Borchardt mean.
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spelling doaj-art-fbf4ed29da7845d4b42c5512b0b853152025-02-03T01:07:29ZengWileyJournal of Applied Mathematics1110-757X1687-00422013-01-01201310.1155/2013/807623807623Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic MeansZai-Yin He0Yu-Ming Chu1Miao-Kun Wang2Department of Mathematics, Huzhou Teachers College, Huzhou 313000, ChinaSchool of Mathematics and Computation Science, Hunan City University, Yiyang 413000, ChinaSchool of Mathematics and Computation Science, Hunan City University, Yiyang 413000, ChinaFor a,b>0 with a≠b, the Schwab-Borchardt mean SB(a,b) is defined as SB(a,b)={b2-a2/cos-1(a/b) if a<b,a2-b2/cosh-1(a/b) if a>b. In this paper, we find the greatest values of α1 and α2 and the least values of β1 and β2 in [0,1/2] such that H(α1a+(1-α1)b,α1b+(1-α1)a)<SAH(a,b)<H(β1a+(1-β1)b,β1b+(1-β1)a) and H(α2a+(1-α2)b,α2b+(1-α2)a)<SHA(a,b)<H(β2a+(1-β2)b,β2b+(1-β2)a). Similarly, we also find the greatest values of α3 and α4 and the least values of β3 and β4 in [1/2,1] such that C(α3a+(1-α3)b,α3b+(1-α3)a)<SCA(a,b)<C(β3a+(1-β3)b,β3b+(1-β3)a) and C(α4a+(1-α4)b,α4b+(1-α4)a)<SAC(a,b)<C(β4a+(1-β4)b,β4b+(1-β4)a). Here, H(a,b)=2ab/(a+b), A(a,b)=(a+b)/2, and C(a,b)=(a2+b2)/(a+b) are the harmonic, arithmetic, and contraharmonic means, respectively, and SHA(a,b)=SB(H,A), SAH(a,b)=SB(A,H), SCA(a,b)=SB(C,A), and SAC(a,b)=SB(A,C) are four Neuman means derived from the Schwab-Borchardt mean.http://dx.doi.org/10.1155/2013/807623
spellingShingle Zai-Yin He
Yu-Ming Chu
Miao-Kun Wang
Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic Means
Journal of Applied Mathematics
title Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic Means
title_full Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic Means
title_fullStr Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic Means
title_full_unstemmed Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic Means
title_short Optimal Bounds for Neuman Means in Terms of Harmonic and Contraharmonic Means
title_sort optimal bounds for neuman means in terms of harmonic and contraharmonic means
url http://dx.doi.org/10.1155/2013/807623
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AT miaokunwang optimalboundsforneumanmeansintermsofharmonicandcontraharmonicmeans