A Harmonic Mean Inequality for the q-Gamma and q-Digamma Functions

被引:3
作者
Bouali, Mohamed [1 ]
机构
[1] Fac Sci Tunis, Inst Preparatoire Etud Ingn Tunis, Campus Univ El Manar, El Manar Tunis 2092, Tunisia
关键词
q-Digamma function; q-Psi function; q-Gamma function; Gamma function; Digamma function; BOUNDS;
D O I
10.2298/FIL2112105B
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
We prove among others results that the harmonic mean of Gamma(q)(x) and Gamma(q)(1/x) is greater than or equal to 1 for arbitrary x > 0, and q is an element of J where J is a subset of [0, +infinity). Also, we prove that there is a unique real number p(0) is an element of (1, 9/2), such that for q is an element of (0, p(0)), psi(q)(1) is the minimum of the harmonic mean of psi(q)(x) and psi(q)(1/x) for x > 0 and for q is an element of (p(0), +infinity), psi(q)(1) is the maximum. Our results generalize some known inequalities due to Alzer and Gautschi.
引用
收藏
页码:4105 / 4119
页数:15
相关论文
共 25 条
[1]   Sharp inequalities for the digamma and polygamma functions [J].
Alzer, H .
FORUM MATHEMATICUM, 2004, 16 (02) :181-221
[2]  
Alzer H, 2001, MATH NACHR, V222, P5, DOI 10.1002/1522-2616(200102)222:1<5::AID-MANA5>3.0.CO
[3]  
2-Q
[4]   Inequalities for the gamma function [J].
Alzer, H .
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY, 2000, 128 (01) :141-147
[5]  
Alzer H., 2001, AEQUATIONES MATH, V61, P151, DOI [10.1007/s000100050167, DOI 10.1007/S000100050167]
[6]   Inequalities for the gamma and q-gamma functions [J].
Alzer, Horst ;
Grinshpan, Arcadii Z. .
JOURNAL OF APPROXIMATION THEORY, 2007, 144 (01) :67-83
[7]   A harmonic mean inequality for the digamma function and related results [J].
Alzer, Horst ;
Jameson, Graham .
RENDICONTI DEL SEMINARIO MATEMATICO DELLA UNIVERSITA DI PADOVA, 2017, 137 :203-209
[8]  
Askey Richard, 1978, Appl. Anal, V8, P125
[9]  
Batir N., 2005, J INEQUAL PURE APPL, V6, P1
[10]   On some properties of digamma and polygamma functions [J].
Batir, Necdet .
JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS, 2007, 328 (01) :452-465