期刊名称：International Journal of Mathematics and Mathematical Sciences
印刷版ISSN：0161-1712
电子版ISSN：1687-0425
出版年度：2006
卷号：2006
DOI：10.1155/IJMMS/2006/76782
出版社：Hindawi Publishing Corporation
摘要：The main purpose of this note is to establish an
identity which states that the function sinx/x is a power series of (π2−4x2) with positive coefficients for all x≠0. This enable us to obtain a much stronger Jordan's inequality
than that obtained before.
