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Junior Balkan Mathematical Olympiad 2024- P1

Source: JBMO 2024

June 27, 2024
JBMOBalkaninequalitiesalgebra

Problem Statement

Let a,b,ca, b, c be positive real numbers such that
a2+b2+c2=14.a^2 + b^2 + c^2 = \frac{1}{4}.
Prove that
1b2+c2+1c2+a2+1a2+b22(a+b)(b+c)(c+a).\frac{1}{\sqrt{b^2 + c^2}} + \frac{1}{\sqrt{c^2 + a^2}} + \frac{1}{\sqrt{a^2 + b^2}} \le \frac{\sqrt{2}}{(a + b)(b + c)(c + a)}.
Proposed by Petar Filipovski, Macedonia