MathDB
Understanding the condition

Source: Science ON 2021 grade IX/3

March 8, 2021
Inequalityalgebraidentities

Problem Statement

Real numbers a,b,ca,b,c with 0a,b,c10\le a,b,c\le 1 satisfy the condition a+b+c=1+2(1a)(1b)(1c).a+b+c=1+\sqrt{2(1-a)(1-b)(1-c)}. Prove that 1a2+1b2+1c2332.\sqrt{1-a^2}+\sqrt{1-b^2}+\sqrt{1-c^2}\le \frac{3\sqrt 3}{2}.
(Nora Gavrea)