On co-Farthest Points in Normed Linear Spaces

Theory of Approximation and Applications

مقاله 8، دوره 12، شماره 1، مرداد 2018، صفحه 117-126   

نوع مقاله: Research Articles

نویسندگان

Hamid Mazaheri Tehrani^{* 1}؛ S. M. Moosavi²؛ M. A Dehghan²؛ Z. Bizhanzadeh¹

¹Faculty of Mathematics, Yazd University, Yazd, Iran

²Department of Mathematics, Rafsanjan University, Rafsanjan, Iran

چکیده

In this paper, we consider the concepts co-farthest points in
normed linear spaces. At first, we define farthest points, farthest orthogonality
in normed linear spaces. Then we define co-farthest points, co-remotal sets,
co-uniquely sets and co-farthest maps. We shall prove some theorems about
co-farthest points, co-remotal sets. We obtain a necessary and coecient conditions
about co-farthest points and dual space. Also, we show that every
co-remotal set is co-uniquely set.

کلیدواژه‌ها

Farthest points؛ Co-farthest points؛ Co-farthest map