Journal of Inequalities and Applications 
Volume 2 (1998), Issue 4, Pages 373-380
doi:10.1155/S102558349800023X

On some inequalities and stability results related to the exponential function

Claudi Alsina1 and Roman Ger2

 1Sec. Matemàtiques Informàtica, Univ. Politècnica de Catalunya, Diagonal 649, Barcelona 08028, Spain
2lnstitute of Mathematics, Silesian University, ul. Bankowa 14, Katowice 40-007, Poland
Received 12 November 1997; Revised 20 February 1998

Abstract

Some inequalities related to the exponential function are solved and the stability of the functional equations f′(x)=f(x) and (f(y)−f(x))/(y−x)=f((x+y)/2) is studied.