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Math Olympiad Workshops
kokcio   1
N an hour ago by GreekIdiot
Hello Math Enthusiasts!

I'm excited to announce a series of free Math Olympiad Workshops designed to help you sharpen your problem-solving skills in preparation for competitions. Whether you're a beginner or a seasoned competitor, these workshops aim to provide a supportive, challenging, and collaborative environment to explore advanced math topics.

Workshop Overview

Duration: 6 months (with the possibility of extending based on participant interest)

Structure: Weekly cycles, each dedicated to one of the main areas of Math Olympiad:
Week 1: Number Theory
Week 2: Geometry
Week 3: Algebra
Week 4: Combinatorics

Weekly Format
Monday: Problem Set Release: Approximately 30 problems will be posted covering the week's topic, which you will have chance to discuss.
Throughout the Week:
Theory Notes: I will share helpful theory and insights relevant to the problem set, giving you the tools you need to approach the problems.
Submission Opportunity: You can work on the problems and submit your solutions. I’ll review your work and provide feedback.
End of the Week: Solutions Post: I’ll release detailed solutions to all problems from the problem set.
Leaderboard: For those interested, we can maintain a table tracking participants who solve the most problems during the week.

Cycle Finale – Mock Contest
At the end of each 4-week cycle, we’ll host a Mock Contest featuring 4 problems (one from each topic). This is a great chance to simulate the competition environment and test your skills in a timed setting. I will review and provide feedback on your contest submissions.

Starting date: June 2

How to participate? Just write /signup under this post.

I believe these workshops will provide a comprehensive, engaging, and collaborative way to tackle Math Olympiad problems. I'm looking forward to seeing your creativity and problem-solving prowess!
If you have any questions or suggestions, please leave a comment below.
1 reply
kokcio
Today at 12:11 AM
GreekIdiot
an hour ago
Mathematics
slimshady360   0
an hour ago
Solve this
0 replies
slimshady360
an hour ago
0 replies
Solve this
slimshady360   0
an hour ago
Math problem
0 replies
slimshady360
an hour ago
0 replies
Turbo the Snail
GreekIdiot   1
N an hour ago by aidenkim119
Let $n$ be a positive integer. There are $n$ circles drawn on a chalkboard such that any two circles intersect at $2$ distinct points and no $3$ circles pass through the same point. Turbo the snail slides along the circles in the following manner, leaving snail goo behind. Initially he moves on one of the circles in clockwise direction. He keeps sliding along until he reaches an intersection with another circle. Then, he continues his journey on this new circle and also changes the direction he is moving in. We define a snail orbit to be the covering of the whole surface of a circle with turbo's goo, and specifically only a single layer of it. Prove that for every odd $n$ there exists at least one configuration of $n$ circles with a single snail orbit, and find all $n$ such that there is exactly one of the aforementioned configuration type.
1 reply
GreekIdiot
an hour ago
aidenkim119
an hour ago
Mathematics
slimshady360   0
an hour ago
Solve this
0 replies
slimshady360
an hour ago
0 replies
Olympiad question
slimshady360   0
an hour ago
Let a,b,c be positive real numbers such that a + b+c = 3abc. Prove that
a2 +b2 +c2 +3 ≥2(ab+bc+ca)
0 replies
slimshady360
an hour ago
0 replies
Infinite sequences.. welp
navi_09220114   2
N an hour ago by ja.
Source: Own. Malaysian IMO TST 2025 P1
Determine all integers $n\ge 2$ such that for any two infinite sequences of positive integers $a_1<a_2< \cdots $ and $b_1, b_2, \cdots$, such that $a_i\mid a_j$ for all $i<j$, there always exists a real number $c$ such that $$\lfloor{ca_i}\rfloor \equiv b_i \pmod {n}$$for all $i\ge 1$.

Proposed by Wong Jer Ren & Ivan Chan Kai Chin
2 replies
navi_09220114
Yesterday at 12:52 PM
ja.
an hour ago
An important lemma of isogonal conjugate points
buratinogigle   0
2 hours ago
Source: Own
Let $P$ and $Q$ be two isogonal conjugate with respect to triangle $ABC$. Let $S$ and $T$ be two points lying on the circle $(PBC)$ such that $PS$ and $PT$ are perpendicular and parallel to bisector of $\angle BAC$, respectively. Prove that $QS$ and $QT$ bisect two arcs $BC$ containing $A$ and not containing $A$, respectively, of $(ABC)$.
0 replies
buratinogigle
2 hours ago
0 replies
Orders and primes
GreekIdiot   0
2 hours ago
Find whether there exist prime numbers $p$ such that there exists an integer $a$ satisfying
$i)a^7 \equiv 1 \: mod \: p$, with $ord_{p}(a)=7$
$ii)a^3+a+1 \equiv 0 \: mod \: p$
0 replies
GreekIdiot
2 hours ago
0 replies
Divisibility
RenheMiResembleRice   2
N 2 hours ago by navier3072
Source: Byer
Prove that for all n ∈ ℕ, 133|($11^{\left(n+2\right)}+12^{\left(2n+1\right)}$).
2 replies
RenheMiResembleRice
Today at 3:07 AM
navier3072
2 hours ago
Inequality with x, y
bel.jad5   6
N Mar 20, 2025 by sqing
Source: Own
Let x and y positive real numbers such that: $x^2+y^2+xy=3$. Find the maximum of $x^2y$
6 replies
bel.jad5
Sep 18, 2016
sqing
Mar 20, 2025
Inequality with x, y
G H J
G H BBookmark kLocked kLocked NReply
Source: Own
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bel.jad5
3750 posts
#1 • 2 Y
Y by Adventure10, Mango247
Let x and y positive real numbers such that: $x^2+y^2+xy=3$. Find the maximum of $x^2y$
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Dr Sonnhard Graubner
16100 posts
#2 • 1 Y
Y by Adventure10
bel.jad5 wrote:
Let x and y positive real numbers such that: $x^2+y^2+xy=3$. Find the maximum of $x^2y$

hello, we get this here $$\left\{\frac{1}{3} \sqrt{2 \left(69-11 \sqrt{33}\right)},\left\{x\to
   \sqrt{\frac{1}{6} \left(15-\sqrt{33}\right)},y\to \frac{2 \sqrt{2 \left(69-11
   \sqrt{33}\right)}}{15-\sqrt{33}}\right\}\right\}$$Sonnhard.
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bel.jad5
3750 posts
#3 • 2 Y
Y by Adventure10, Mango247
Yes true.
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ali3985
1042 posts
#4 • 3 Y
Y by bel.jad5, Adventure10, Mango247
bel.jad5 wrote:
Let x and y positive real numbers such that: $x^2+y^2+xy=3$. Find the maximum of $x^2y$

If we put $y=kx$, with k a positive real then

$x^2+y^2+y^2=x^2(k^2+k+1)=3$

$x^2y=kx^3=\frac{3\sqrt{3}k}{(k^2+k+1)^\frac{3}{2}}$

setting $f(k)=\frac{3\sqrt{3}k}{(k^2+k+1)^\frac{3}{2}}$

Then $f'(k)=\frac{3\sqrt{3}(-4k^2-k+2)}{(k^2+k+1)^\frac{5}{2}}$

$f'(k)=0 \iff k_{1}=\frac{\sqrt{33}-1}{8}$ or $k_{2}=\frac{-\sqrt{33}-1}{8} < 0 $

and we get

$f(k) \le f(k_{1})$
This post has been edited 1 time. Last edited by ali3985, Sep 22, 2016, 9:40 PM
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sqing
41181 posts
#5 • 2 Y
Y by Adventure10, Mango247
http://www.artofproblemsolving.com/community/c4t243f4h1309979_inequality:
Let $x$ and $y$ be nonnegative real numbers such that $x+y+\sqrt{2x^2+2xy+3y^2}=4$.
Prove that$$x^2y\leq32\left(\sqrt{\frac{5}{3}}-1\right)^3$$
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sqing
41181 posts
#6 • 2 Y
Y by Adventure10, Mango247
sqing wrote:
http://www.artofproblemsolving.com/community/c4t243f4h1309979_inequality:
Let $x$ and $y$ be nonnegative real numbers such that $x+y+\sqrt{2x^2+2xy+3y^2}=4$.
Prove that$$x^2y\leq32\left(\sqrt{\frac{5}{3}}-1\right)^3$$
Proof(elecaii1981):
Attachments:
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sqing
41181 posts
#7
Y by
Let $ a,b $ be nonnegative real numbers such that $ a^2+b^2+ab=3 . $ Prove that
$$ a^3b\leq \frac{ 13  \sqrt{13}-35}{3}  $$Equality holds when $ a=\frac{\sqrt{11-\sqrt{13}}}{2} ,b= \frac{\sqrt{5-\sqrt{13}}}{2}. $
$$ a^2b\leq \frac{\sqrt{138-22 \sqrt{33}} }{3}  $$Equality holds when $ a=\sqrt{\frac{15-\sqrt{33}}{6}},b=\sqrt{\frac{9-\sqrt{33}}{6}}. $
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