Mapping Phi-p in normed linear spaces and characterization of orthogonality problem of best approximation in 2-norm

Abstract

In order to characterizations of best approximations have been given in 2-norm space (X, || .,|| ). Some generalization of the function phi-p of Dragomir type have been given in the context where the said generalization help to formulate the characterizations what have been proposed in this article.