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Derivative in nationals?

Source: Mongolian Mathematical Olympiad 2024 P4

April 12, 2024
calculusderivativealgebraInequalityBruh

Problem Statement

Let P(x)P(x) and Q(x)Q(x) be polynomials with nonnegative coefficients. We denote by P(x)P'(x) the derivative of P(x)P(x). Suppose that P(0)=Q(0)=0P(0)=Q(0)=0 and Q(1)1P(0)Q(1) \leq 1 \leq P'(0).
(1)(1) Prove that 0Q(x)xP(x)0 \leq Q(x) \leq x \leq P(x) for all 0x10 \leq x \leq 1. (2)(2) Prove that P(Q(x))Q(P(x))P(Q(x)) \leq Q(P(x)) for all 0x10 \leq x \leq 1.
Proposed by Otgonbayar Uuye.