Problem

Source: BIMO 1 Christmas Test 2024 P8

Tags: geometry



Let $ABC$ be a non-isosceles and acute triangle. $X$ is a point on arc $BC$ not containing $A$ such that $BA-CA = CX-BX$. The incircle of $\triangle ABC$ touches $AC$ and $AB$ at $E$ and $F$ respectively. The $X$-excircle of $\triangle XBC$ touches $XC$ and $XB$ at $Y$ and $Z$ respectively. Let $T$ be such that $TA$ and $TX$ bisects $\angle BAC$ and $\angle BXC$ respectively. Prove that $T$ lies on the radical axis of circles $(BFZ)$ and $(CEY)$. (Proposed by Chuah Jia Herng)