MathDB
2014-2015 Spring OMO #17

Source:

April 14, 2015
Online Math Open

Problem Statement

Let A,B,M,C,DA,B,M,C,D be distinct points on a line such that AB=BM=MC=CD=6.AB=BM=MC=CD=6. Circles ω1\omega_1 and ω2\omega_2 with centers O1O_1 and O2O_2 and radius 44 and 99 are tangent to line ADAD at AA and DD respectively such that O1,O2O_1,O_2 lie on the same side of line AD.AD. Let PP be the point such that PBO1MPB\perp O_1M and PCO2M.PC\perp O_2M. Determine the value of PO22PO12.PO_2^2-PO_1^2.
Proposed by Ray Li