MathDB

ABC

Source: Iran 2005

August 27, 2005

geometryIrantrigonometryTrigonometric Equations

Problem Statement

Suppose in triangle

ABC

incircle touches the side

BC

P

and

\angle APB=\alpha

. Prove that :

\frac1{p-b}+\frac1{p-c}=\frac2{rtg\alpha}