MathDB
xf(xy)+f(-y)=xf(x)

Source: Dutch BxMO/EGMO Team Selection Test 2014 P2

July 17, 2014
functionalgebra proposedalgebra

Problem Statement

Find all functions f:R\{0}Rf:\mathbb{R}\backslash\{0\}\rightarrow\mathbb{R} for which xf(xy)+f(y)=xf(x)xf(xy) + f(-y) = xf(x) for all non-zero real numbers x,yx, y.