Problem

Source: 2022 Saudi Arabia January Camp Test 2.4 BMO + EGMO TST

Tags: algebra, functional, functional equation



Consider the function $f : R^+ \to R^+$ and satisfying $$f(x + 2y + f(x + y)) = f(2x) + f(3y), \,\, \forall \,\, x, y > 0.$$ 1. Find all functions $f(x)$ that satisfy the given condition. 2. Suppose that $f(4\sin^4x)f(4\cos^4x) \ge f^2(1)$ for all $x \in \left(0\frac{\pi}{2}\right) $. Find the minimum value of $f(2022)$.