MathDB

26

Part of 1979 IMO Shortlist

Problems(1)

Prove that the functional equations are equivalent

Source:

9/15/2010
Prove that the functional equations f(x+y)=f(x)+f(y),f(x + y) = f(x) + f(y), \text{and} \qquad f(x + y + xy) = f(x) + f(y) + f(xy)   (x, y \in \mathbb R) are equivalent.
algebrafunctional equationIMO ShortlistIMO 1979