Polynomials close to 0 resp. 1 on disjoint sets

For disjoint compact subsets I, J of a real interval [A, B] construction is given for polynomials P-n of degree n = 1,2,... that approximate 0 on I and 1 on J with geometric rate, vanish (in a given order) at finitely many given points of I, take the value 1 (in a given order) at finitely given poin...

Teljes leírás

Elmentve itt :
Bibliográfiai részletek
Szerző: Totik Vilmos
Dokumentumtípus: Cikk
Megjelent: 2020
Sorozat:JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS 482 No. 2
doi:10.1016/j.jmaa.2019.123549

mtmt:31431163
Online Access:http://publicatio.bibl.u-szeged.hu/21007
Leíró adatok
Tartalmi kivonat:For disjoint compact subsets I, J of a real interval [A, B] construction is given for polynomials P-n of degree n = 1,2,... that approximate 0 on I and 1 on J with geometric rate, vanish (in a given order) at finitely many given points of I, take the value 1 (in a given order) at finitely given points of J, and otherwise lie in between 0 and 1 on [A, B] . When I and J consist of alternating intervals, then P-n can also be monotone on each subinterval of [A, B] \ (I U J) . Some further consequences (like approximation of piecewise constant functions or the trigonometric variant) are also considered. (C) 2019 Elsevier Inc. All rights reserved.
Terjedelem/Fizikai jellemzők:Terjedelem: 13-Azonosító: 123549
ISSN:0022-247X