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MathNet 2021 — Part 02 Question 8

Math Olympiad Vault · MathNet 2021 — Part 02

Question 8

Let $ABC$ be an acute triangle such that $AB \lt AC$. Let $\omega$ be the circumcircle of $ABC$ and assume that the tangent to $\omega$ at $A$ intersects the line $BC$ at $D$. Let $\Omega$ be the circle with center $D$ and radius $AD$. Denote by $E$ the second intersection point of $\omega$ and $\Omega$. Let $M$ be the midpoint of $BC$. If the line $BE$ meets $\Omega$ again at $X$, and the line $CX$ meets $\Omega$ for the second time at $Y$, show that $A, Y$ and $M$ are collinear.

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