On Inflection Points of the Lehmer Mean Function

Abstract

We prove that the Lehmer mean function of two or three positive numbers has always one and only one inflection point. We further show that in case of two numbers, the inflection point is $p^\star = 1$, and we discuss the location of the inflection point in case of three numbers. We furthermore provide an example of a Lehmer mean function with more than one inflection point and provide simple bounds on the number of inflection points for arbitrary many numbers.