A Fixed Point Theorem and its Application to Best Approximation

The object of this paper is twofold. First, a fixed point theorem of G.L. Cain, Jr. and M. Z. Nashed [1] is generalized. Second, the theorem (Theoreml) is utilized to obtain theorems on best approximation which extend and unify the results of Meinardus [2], Singh [ 3—4 ], and Sahney Singh-Whitfield [5].