کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1138394 1489217 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Infinite family of approximations of the Digamma function
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی کنترل و سیستم های مهندسی
پیش نمایش صفحه اول مقاله
Infinite family of approximations of the Digamma function
چکیده انگلیسی

The aim of this work is to find “good” approximations to the Digamma function ΨΨ. We construct an infinite family of “basic” functions {Ia,a∈[0,1]}{Ia,a∈[0,1]} covering the Digamma function. These functions are shown to approximate ΨΨ locally and asymptotically, and it is shown that for any x∈R+x∈R+, there exists an aa such that Ψ(x)=Ia(x)Ψ(x)=Ia(x). Local and global bounding error functions are found and, as a consequence, new inequalities for the Digamma function are introduced. The approximations are compared to another, well-known, approximation of the Digamma function and we show that an infinite number of members of the family are better.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Mathematical and Computer Modelling - Volume 43, Issues 11–12, June 2006, Pages 1329–1336
نویسندگان
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