Difference between revisions of "2020 USAMO Problems/Problem 1"

(Video Solution)
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==Problem 1==
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Let <math>ABC</math> be a fixed acute triangle inscribed in a circle <math>\omega</math> with center <math>O</math>. A variable point <math>X</math> is chosen on minor arc <math>AB</math> of <math>\omega</math>, and segments <math>CX</math> and <math>AB</math> meet at <math>D</math>. Denote by <math>O_1</math> and <math>O_2</math> the circumcenters of triangles <math>ADX</math> and <math>BDX</math>, respectively. Determine all points <math>X</math> for which the area of triangle <math>OO_1O_2</math> is minimized.
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==Video Solution==
 
==Video Solution==
 
https://www.youtube.com/watch?v=m157cfw0vdE
 
https://www.youtube.com/watch?v=m157cfw0vdE

Revision as of 15:21, 15 September 2022

Problem 1

Let $ABC$ be a fixed acute triangle inscribed in a circle $\omega$ with center $O$. A variable point $X$ is chosen on minor arc $AB$ of $\omega$, and segments $CX$ and $AB$ meet at $D$. Denote by $O_1$ and $O_2$ the circumcenters of triangles $ADX$ and $BDX$, respectively. Determine all points $X$ for which the area of triangle $OO_1O_2$ is minimized.


Video Solution

https://www.youtube.com/watch?v=m157cfw0vdE