A SIMPLE PROOF OF OPPENHEIM'S DOUBLE INEQUALITY RELATING TO THE COSINE AND SINE FUNCTIONS

被引:8
|
作者
Qi, Feng [1 ]
Luo, Qiu-Ming [2 ]
Guo, Bai-Ni [3 ]
机构
[1] Inner Mongolia Univ Nationalities, Coll Math, Tongliao City 028043, Inner Mongolia, Peoples R China
[2] Chongqing Normal Univ, Dept Math, Chongqing 401331, Peoples R China
[3] Henan Polytech Univ, Sch Math & Informat, Jiaozuo City 454010, Henan Province, Peoples R China
来源
JOURNAL OF MATHEMATICAL INEQUALITIES | 2012年 / 6卷 / 04期
关键词
Simple proof; Oppenheim's double inequality; cosine function; sine function; monotonicity; JORDANS INEQUALITY;
D O I
10.7153/jmi-06-63
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
In the paper, the authors provide a simple proof of Oppenheim's double inequality relating to the cosine and sine functions. In passing, the authors survey this topic.
引用
收藏
页码:645 / 654
页数:10
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