Wardowski (2012) introduced a new type of contractive mapping and proved a fixed point result in complete metric spaces as
a generalization of Banach contraction principle. In this paper, we introduce a notion of generalized F-contraction mappings
which is used to prove a fixed point result for generalized nonexpansive mappings on star-shaped subsets of normed linear spaces.
Some theorems on invariant approximations in normed linear spaces are also deduced. Our results extend, unify, and generalize
comparable results in the literature.