New Inequalities of Cusa–Huygens Type

Using the power series expansions of the functions <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo form="prefix">cot</mo><mi>x</mi><mo>,</mo><mn>1<...

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Main Author: Ling Zhu
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/9/17/2101
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author Ling Zhu
author_facet Ling Zhu
author_sort Ling Zhu
collection DOAJ
description Using the power series expansions of the functions <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo form="prefix">cot</mo><mi>x</mi><mo>,</mo><mn>1</mn><mo>/</mo><mo form="prefix">sin</mo><mi>x</mi></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1</mn><mo>/</mo><msup><mo form="prefix">sin</mo><mn>2</mn></msup><mi>x</mi></mrow></semantics></math></inline-formula>, and the estimate of the ratio of two adjacent even-indexed Bernoulli numbers, we improve Cusa–Huygens inequality in two directions on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mfenced separators="" open="(" close=")"><mn>0</mn><mo>,</mo><mi>π</mi><mo>/</mo><mn>2</mn></mfenced></semantics></math></inline-formula>. Our results are much better than those in the existing literature.
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spelling doaj.art-adaf10de8a3f42ddb31daf75f5f73bb82023-11-22T10:57:55ZengMDPI AGMathematics2227-73902021-08-01917210110.3390/math9172101New Inequalities of Cusa–Huygens TypeLing Zhu0Department of Mathematics, Zhejiang Gongshang University, Hangzhou 310018, ChinaUsing the power series expansions of the functions <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo form="prefix">cot</mo><mi>x</mi><mo>,</mo><mn>1</mn><mo>/</mo><mo form="prefix">sin</mo><mi>x</mi></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1</mn><mo>/</mo><msup><mo form="prefix">sin</mo><mn>2</mn></msup><mi>x</mi></mrow></semantics></math></inline-formula>, and the estimate of the ratio of two adjacent even-indexed Bernoulli numbers, we improve Cusa–Huygens inequality in two directions on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mfenced separators="" open="(" close=")"><mn>0</mn><mo>,</mo><mi>π</mi><mo>/</mo><mn>2</mn></mfenced></semantics></math></inline-formula>. Our results are much better than those in the existing literature.https://www.mdpi.com/2227-7390/9/17/2101sharp the double inequalities of Cusa–Huygens typecircular functionsBernoulli numbers
spellingShingle Ling Zhu
New Inequalities of Cusa–Huygens Type
Mathematics
sharp the double inequalities of Cusa–Huygens type
circular functions
Bernoulli numbers
title New Inequalities of Cusa–Huygens Type
title_full New Inequalities of Cusa–Huygens Type
title_fullStr New Inequalities of Cusa–Huygens Type
title_full_unstemmed New Inequalities of Cusa–Huygens Type
title_short New Inequalities of Cusa–Huygens Type
title_sort new inequalities of cusa huygens type
topic sharp the double inequalities of Cusa–Huygens type
circular functions
Bernoulli numbers
url https://www.mdpi.com/2227-7390/9/17/2101
work_keys_str_mv AT lingzhu newinequalitiesofcusahuygenstype