Solution of the Ulam stability problem for Euler-Lagrange-Jensen k-quintic mappings

In this paper, we are introducing pertinent Euler-Lagrange-Jensen type k-quintic functional equations and investigate the Ulam stability' of these new k-quintic functional mappings f:XY, where X is a real normed linear space and Y a real complete normed linear space. We also solve the Ulam stability problem for Euler-Lagrange-Jensen alternative k-quintic mappings. Copyright (c) 2016 John Wiley & Sons, Ltd.