MathDB

9

Part of 2009 Kyrgyzstan National Olympiad

Problems(1)

Old inequality

Source: Kyrgyzstan TST 2009

4/14/2009
For any positive a1,a2,...,an a_1 ,a_2 ,...,a_n prove that \frac {{a_1 }} {{a_2 \plus{} a_3 }} \plus{} \frac {{a_2 }} {{a_3 \plus{} a_4 }} \plus{} ... \plus{} \frac {{a_n }} {{a_1 \plus{} a_2 }} > \frac {n} {4} holds.
inequalitiesinequalities proposed