On co-Farthest Points in Normed Linear Spaces

Subject Areas : Applied Mathematics

Hamid Mazaheri Tehrani ¹ (Faculty of Mathematics, Yazd University, Yazd, Iran)
S. M. Moosavi ² (Department of Mathematics, Rafsanjan University, Rafsanjan, Iran)
M. A Dehghan ³ (Department of Mathematics, Rafsanjan University, Rafsanjan, Iran)
Z. Bizhanzadeh ⁴ (Faculty of Mathematics, Yazd University, Yazd, Iran)

Received: 2016-11-12 Accepted : 2017-03-27 Published : 2018-05-01

Keywords: Farthest points, Co-farthest map, Co-farthest points,

Abstract :

In this paper, we consider the concepts co-farthest points innormed linear spaces. At first, we define farthest points, farthest orthogonalityin 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 aboutco-farthest points, co-remotal sets. We obtain a necessary and coecient conditionsabout co-farthest points and dual space. Also, we show that everyco-remotal set is co-uniquely set.