On the equality problem of two-variable Bajraktarević means under first-order differentiability assumptions

Zsolt Páles, Amr Zakaria

The equality problem of the two-variable Bajraktarević means can be expressed as the functional equation $$ \left(\frac{f}{g}\right)^{-1}\bigg(\frac{f(x)+f(y)}{g(x)+g(y)}\bigg) =\l…