Best Co-approximation and Worst Approximation by Closed Unit Balls
Subject Areas : Mathematical Analysis
Hamid
Tehrani
1
(Department of Mathematics, Yazd University, Yazd, Iran)
Keywords: Copoximinal, Closed Unit Balls, Qcoproximinal, Uniquely remotal, Cochebyshevl,
Abstract :
‎A kind of approximation‎, ‎called best coapproximation was‎ introduced and discussed in normed linear spaces by C‎. ‎Franchetti and M‎. Furi in 1972‎. ‎Subsequently‎, ‎this study was taken up by several researchers‎ in different abstract spaces‎. In this paper‎, ‎we consider best coapproximation by closed unit balls‎. ‎We define qcoproximinal and coremotal‎, ‎and find some theorems.