{ "id": "2408.15212", "version": "v1", "published": "2024-08-27T17:19:31.000Z", "updated": "2024-08-27T17:19:31.000Z", "title": "Chebyshev approximation of $x^m (-\\log x)^l$ in the interval $0\\le x \\le 1$", "authors": [ "Richard J. Mathar" ], "comment": "9 pages, no figures. Integrals table in the anc directory", "categories": [ "math.CA" ], "abstract": "The series expansion of $x^m (-\\log x)^l$ in terms of the shifted Chebyshev Polynomials $T_n^*(x)$ requires evaluation of the integral family $\\int_0^1 x^m (-\\log x)^l dx / \\sqrt{x-x^2}$. We demonstrate that these can be reduced by partial integration to sums over integrals with exponent $m=0$ which have known representations as finite sums over polygamma functions.", "revisions": [ { "version": "v1", "updated": "2024-08-27T17:19:31.000Z" } ], "analyses": { "subjects": [ "26A09", "41A10", "G.1.2" ], "keywords": [ "chebyshev approximation", "polygamma functions", "series expansion", "finite sums", "partial integration" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable" } } }