MathDB
Putnam 2010 A2

Source:

December 6, 2010
Putnamfunctionintegrationcollege contestsreal analysisslope

Problem Statement

Find all differentiable functions f:RRf:\mathbb{R}\to\mathbb{R} such that f(x)=f(x+n)f(x)nf'(x)=\frac{f(x+n)-f(x)}n for all real numbers xx and all positive integers n.n.