Abstract. A functional equation involving pairs of means is considered. It is shown that there are only constant solutions if continuous differentiability is assumed, and there may be non-constant everywhere differentiable solutions. Various other situations are considered, where less smoothness is assumed on the unknown function.
DOI: 10.14232/actasm-015-805-1
AMS Subject Classification
(1991): 39B22
Keyword(s):
functional equation,
means
Received June 4, 2014, and in revised form September 21, 2015. (Registered under 55/2015.)
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