New Refinements and Improvements of Jordan’s Inequality

Lina Zhang and Xuesi Ma
Additional contact information
Lina Zhang: School of Computer Science and Technology, Henan Polytechnic University, Jiaozuo 454000, China
Xuesi Ma: School of Mathematic and Information Science, Henan Polytechnic University, Jiaozuo 454000, China

Mathematics, 2018, vol. 6, issue 12, 1-8

Abstract: The polynomial bounds of Jordan’s inequality, especially the cubic and quartic polynomial bounds, have been studied and improved in a lot of the literature; however, the linear and quadratic polynomial bounds can not be improved very much. In this paper, new refinements and improvements of Jordan’s inequality are given. We present new lower bounds and upper bounds for strengthened Jordan’s inequality using polynomials of degrees 1 and 2. Our bounds are tighter than the previous results of polynomials of degrees 1 and 2. More importantly, we give new improvements of Jordan’s inequality using polynomials of degree 5, which can achieve much tighter bounds than those previous methods.

Keywords: Jordan’s inequality; polynomial; bound (search for similar items in EconPapers)
JEL-codes: C (search for similar items in EconPapers)
Date: 2018
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/2227-7390/6/12/284/pdf (application/pdf)
https://www.mdpi.com/2227-7390/6/12/284/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jmathe:v:6:y:2018:i:12:p:284-:d:185627

Access Statistics for this article

Mathematics is currently edited by Ms. Emma He

More articles in Mathematics from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().