“…This simple inequality has motivated a large number of research papers concerning its new proofs, various generalizations, sharpness and applications (e.g., see Zhu [2,3],Özban [4], Debnath and Zhao [5], Yuefeng [6], Wu [7], Mercer et al [8]). In a recent paper Wu and Debnath [9] established the following sharp lower and upper bounds for the function ( sin x x ) as an improvement of Jordan's inequality…”