Difference between revisions of "2014 USAJMO Problems"
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===Problem 2=== | ===Problem 2=== | ||
+ | Let <math>\triangle{ABC}</math> be a non-equilateral, acute triangle with <math>\angle A=60\textdegrees</math>, and let <math>O</math> and <math>H</math> denote the circumcenter and orthocenter of <math>\triangle{ABC}</math>, respectively. | ||
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+ | (a) Prove that line <math>OH</math> intersects both segments <math>AB</math> and <math>AC</math>. | ||
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+ | (b) Line <math>OH</math> intersects segments <math>AB</math> and <math>AC</math> at <math>P</math> and <math>Q</math>, respectively. Denote by <math>s</math> and <math>t</math> the respective areas of triangle <math>APQ</math> and quadrilateral <math>BPQC</math>. Determine the range of possible values for <math>s/t</math>. | ||
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[[2014 USAJMO Problems/Problem 2|Solution]] | [[2014 USAJMO Problems/Problem 2|Solution]] | ||
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===Problem 3=== | ===Problem 3=== | ||
Let <math>\mathbb{Z}</math> be the set of integers. Find all functions <math>f : \mathbb{Z} \rightarrow \mathbb{Z}</math> such that <cmath>xf(2f(y)-x)+y^2f(2x-f(y))=\frac{f(x)^2}{x}+f(yf(y))</cmath> for all <math>x, y \in \mathbb{Z}</math> with <math>x \neq 0</math>. | Let <math>\mathbb{Z}</math> be the set of integers. Find all functions <math>f : \mathbb{Z} \rightarrow \mathbb{Z}</math> such that <cmath>xf(2f(y)-x)+y^2f(2x-f(y))=\frac{f(x)^2}{x}+f(yf(y))</cmath> for all <math>x, y \in \mathbb{Z}</math> with <math>x \neq 0</math>. |
Revision as of 17:13, 29 April 2014
Contents
[hide]Day 1
Problem 1
Let , , be real numbers greater than or equal to . Prove that Solution
Problem 2
Let be a non-equilateral, acute triangle with $\angle A=60\textdegrees$ (Error compiling LaTeX. Unknown error_msg), and let and denote the circumcenter and orthocenter of , respectively.
(a) Prove that line intersects both segments and .
(b) Line intersects segments and at and , respectively. Denote by and the respective areas of triangle and quadrilateral . Determine the range of possible values for .
Problem 3
Let be the set of integers. Find all functions such that for all with .