{ "id": "2411.01591", "version": "v1", "published": "2024-11-03T14:58:18.000Z", "updated": "2024-11-03T14:58:18.000Z", "title": "What do sin$(x)$ and arcsinh$(x)$ have in Common?", "authors": [ "Steven Finch" ], "comment": "24 pages", "categories": [ "math.CA", "cs.DM", "math.CO" ], "abstract": "N. G. de Bruijn (1958) studied the asymptotic expansion of iterates of sin$(x)$ with $0 < x \\leq \\pi/2$. Bencherif & Robin (1994) generalized this result to increasing analytic functions $f(x)$ with an attractive fixed point at 0 and $x > 0$ suitably small. Mavecha & Laohakosol (2013) formulated an algorithm for explicitly deriving required parameters. We review their method, testing it initally on the logistic function $\\ell(x)$, a certain radical function $r(x)$, and later on several transcendental functions. Along the way, we show how $\\ell(x)$ and $r(x)$ are kindred functions; the same is also true for sin$(x)$ and arcsinh$(x)$.", "revisions": [ { "version": "v1", "updated": "2024-11-03T14:58:18.000Z" } ], "analyses": { "subjects": [ "39A20", "11B37", "26A18", "37E05", "41A60", "65D20" ], "keywords": [ "asymptotic expansion", "increasing analytic functions", "logistic function", "transcendental functions", "attractive fixed point" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }