On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant Function

In the study, the authors introduce Qi’s normalized remainder of the Maclaurin power series expansion of the function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ln</mi><mi>sec<...

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Main Authors: Hong-Chao Zhang, Bai-Ni Guo, Wei-Shih Du
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Axioms
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Online Access:https://www.mdpi.com/2075-1680/13/12/860
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author Hong-Chao Zhang
Bai-Ni Guo
Wei-Shih Du
author_facet Hong-Chao Zhang
Bai-Ni Guo
Wei-Shih Du
author_sort Hong-Chao Zhang
collection DOAJ
description In the study, the authors introduce Qi’s normalized remainder of the Maclaurin power series expansion of the function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ln</mi><mi>sec</mi><mi>x</mi><mo>=</mo><mo>−</mo><mi>ln</mi><mi>cos</mi><mi>x</mi></mrow></semantics></math></inline-formula>; in view of a monotonicity rule for the ratio of two Maclaurin power series and by virtue of the logarithmic convexity of the function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><msup><mn>2</mn><mi>x</mi></msup><mo>−</mo><mn>1</mn><mo>)</mo></mrow><mi>ζ</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula> on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>(</mo><mn>1</mn><mo>,</mo><mo>∞</mo><mo>)</mo></mrow></semantics></math></inline-formula>, they prove the logarithmic convexity of Qi’s normalized remainder; with the aid of a monotonicity rule for the ratio of two Maclaurin power series, the authors present the monotonic property of the ratio between two Qi’s normalized remainders.
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spelling doaj-art-1cd686565aeb4668879db72c4b8a31d72025-08-20T02:00:51ZengMDPI AGAxioms2075-16802024-12-01131286010.3390/axioms13120860On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant FunctionHong-Chao Zhang0Bai-Ni Guo1Wei-Shih Du2School of Mathematics and Physics, Hulunbuir University, Hulunbuir 021008, ChinaSchool of Mathematics and Informatics, Henan Polytechnic University, Jiaozuo 454010, ChinaDepartment of Mathematics, National Kaohsiung Normal University, Kaohsiung 824004, TaiwanIn the study, the authors introduce Qi’s normalized remainder of the Maclaurin power series expansion of the function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ln</mi><mi>sec</mi><mi>x</mi><mo>=</mo><mo>−</mo><mi>ln</mi><mi>cos</mi><mi>x</mi></mrow></semantics></math></inline-formula>; in view of a monotonicity rule for the ratio of two Maclaurin power series and by virtue of the logarithmic convexity of the function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><msup><mn>2</mn><mi>x</mi></msup><mo>−</mo><mn>1</mn><mo>)</mo></mrow><mi>ζ</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula> on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>(</mo><mn>1</mn><mo>,</mo><mo>∞</mo><mo>)</mo></mrow></semantics></math></inline-formula>, they prove the logarithmic convexity of Qi’s normalized remainder; with the aid of a monotonicity rule for the ratio of two Maclaurin power series, the authors present the monotonic property of the ratio between two Qi’s normalized remainders.https://www.mdpi.com/2075-1680/13/12/860Bernoulli numberDirichlet eta functionMaclaurin power series expansionRiemann zeta functionStirling number of the second kindQi’s normalized remainder
spellingShingle Hong-Chao Zhang
Bai-Ni Guo
Wei-Shih Du
On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant Function
Axioms
Bernoulli number
Dirichlet eta function
Maclaurin power series expansion
Riemann zeta function
Stirling number of the second kind
Qi’s normalized remainder
title On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant Function
title_full On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant Function
title_fullStr On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant Function
title_full_unstemmed On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant Function
title_short On Qi’s Normalized Remainder of Maclaurin Power Series Expansion of Logarithm of Secant Function
title_sort on qi s normalized remainder of maclaurin power series expansion of logarithm of secant function
topic Bernoulli number
Dirichlet eta function
Maclaurin power series expansion
Riemann zeta function
Stirling number of the second kind
Qi’s normalized remainder
url https://www.mdpi.com/2075-1680/13/12/860
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