MathDB
a+b+c=1

Source: 23rd Austrian-Polish MO 2000

June 27, 2005
inequalitiesinequalities unsolvedalgebra

Problem Statement

If three nonnegative reals aa, bb, cc satisfy a+b+c=1a+b+c=1, prove that 2(1a2)2+(1b2)2+(1c2)2(1+a)(1+b)(1+c)2 \leq \left(1-a^{2}\right)^{2}+\left(1-b^{2}\right)^{2}+\left(1-c^{2}\right)^{2}\leq \left(1+a\right)\left(1+b\right)\left(1+c\right).