On co-Farthest Points in Normed Linear Spaces

Document Type: Research Articles


1 Faculty of Mathematics, Yazd University, Yazd, Iran

2 Department of Mathematics, Rafsanjan University, Rafsanjan, Iran


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.