Inequality
Source: Chinese TST
April 6, 2008
inequalitiesgeometrycircumcircletrigonometryratiocyclic quadrilateralgeometry proposed
Problem Statement
Let be an arbitrary point inside triangle , denote by (different from ) the second intersection of line with the circumcircle of triangle and define similarly. Prove that \left(1 \plus{} 2\cdot\frac {PA}{PA_{1}}\right)\left(1 \plus{} 2\cdot\frac {PB}{PB_{1}}\right)\left(1 \plus{} 2\cdot\frac {PC}{PC_{1}}\right)\geq 8.