Problem

Source: day2 Problem1

Tags: function, induction, limit, algebra proposed, algebra



Find all function $ f: R^+ \rightarrow R^+$ such that for any $ x,y,z \in R^+$ such that $ x+y \ge z$ , $ f(x+y-z) +f(2\sqrt{xz})+f(2\sqrt{yz}) = f(x+y+z)$