{ "id": "1710.01270", "version": "v1", "published": "2017-10-03T16:38:22.000Z", "updated": "2017-10-03T16:38:22.000Z", "title": "A Gronwall-type Trigonometric Inequality", "authors": [ "A. G. Smirnov" ], "comment": "To appear in the American Mathematical Monthly", "categories": [ "math.CA", "math.CV" ], "abstract": "We prove that the absolute value of the $n$th derivative of $\\cos(\\sqrt{x})$ does not exceed $n!/(2n)!$ for all $x>0$ and $n = 0,1,\\ldots$ and obtain a natural generalization of this inequality involving the analytic continuation of $\\cos(\\sqrt{x})$.", "revisions": [ { "version": "v1", "updated": "2017-10-03T16:38:22.000Z" } ], "analyses": { "subjects": [ "26D05" ], "keywords": [ "gronwall-type trigonometric inequality", "absolute value", "natural generalization", "analytic continuation" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }