Abstract
We present sharp upper and lower bounds for the function \(\sin (x)/x\). Our bounds are polynomials of degree 2n, where n is any nonnegative integer.
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We thank the referee for helpful comments.
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Man Kam Kwong: The research of this author is supported by the Hong Kong Government GRF Grant PolyU 5003/12P and the Hong Kong Polytechnic University Grants G-UC22 and G-UA10.
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Alzer, H., Kwong, M.K. On Jordan���s inequality. Period Math Hung 77, 191–200 (2018). https://doi.org/10.1007/s10998-017-0230-z
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DOI: https://doi.org/10.1007/s10998-017-0230-z