IMC 1999 · Problem 4

Day 120 points6th IMC · Keszthely, Hungary

Statement

Find all strictly monotonic functions f:(0,+)(0,+)f : (0, +\infty) \to (0, +\infty) such that f(x2f(x))xf\left( \dfrac{x^2}{f(x)} \right) \equiv x.

Official solution

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