Abstract
In this paper, we introduce the notion of an almost phi(f)-contraction which involves generalized altering distance functions and then we prove the existence and uniqueness of common fixed points for such contractions. As an application invariant approximation results are obtained. Further we investigate a common fixed point result in strongly M-starshaped metric spaces and apply it to obtain an invariant approximation result. Our work includes improvements and extensions of several recent developments of the existing work on fixed point theory. We also furnish some suitable examples to demonstrate the generality of our results on the existing ones.