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H
k a May Highlights and 2025 AoPS Online Class Information
jlacosta   0
May 1, 2025
May is an exciting month! National MATHCOUNTS is the second week of May in Washington D.C. and our Founder, Richard Rusczyk will be presenting a seminar, Preparing Strong Math Students for College and Careers, on May 11th.

Are you interested in working towards MATHCOUNTS and don’t know where to start? We have you covered! If you have taken Prealgebra, then you are ready for MATHCOUNTS/AMC 8 Basics. Already aiming for State or National MATHCOUNTS and harder AMC 8 problems? Then our MATHCOUNTS/AMC 8 Advanced course is for you.

Summer camps are starting next month at the Virtual Campus in math and language arts that are 2 - to 4 - weeks in duration. Spaces are still available - don’t miss your chance to have an enriching summer experience. There are middle and high school competition math camps as well as Math Beasts camps that review key topics coupled with fun explorations covering areas such as graph theory (Math Beasts Camp 6), cryptography (Math Beasts Camp 7-8), and topology (Math Beasts Camp 8-9)!

Be sure to mark your calendars for the following upcoming events:
[list][*]May 9th, 4:30pm PT/7:30pm ET, Casework 2: Overwhelming Evidence — A Text Adventure, a game where participants will work together to navigate the map, solve puzzles, and win! All are welcome.
[*]May 19th, 4:30pm PT/7:30pm ET, What's Next After Beast Academy?, designed for students finishing Beast Academy and ready for Prealgebra 1.
[*]May 20th, 4:00pm PT/7:00pm ET, Mathcamp 2025 Qualifying Quiz Part 1 Math Jam, Problems 1 to 4, join the Canada/USA Mathcamp staff for this exciting Math Jam, where they discuss solutions to Problems 1 to 4 of the 2025 Mathcamp Qualifying Quiz!
[*]May 21st, 4:00pm PT/7:00pm ET, Mathcamp 2025 Qualifying Quiz Part 2 Math Jam, Problems 5 and 6, Canada/USA Mathcamp staff will discuss solutions to Problems 5 and 6 of the 2025 Mathcamp Qualifying Quiz![/list]
Our full course list for upcoming classes is below:
All classes run 7:30pm-8:45pm ET/4:30pm - 5:45pm PT unless otherwise noted.

Introductory: Grades 5-10

Prealgebra 1 Self-Paced

Prealgebra 1
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Prealgebra 2
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Introduction to Algebra A Self-Paced

Introduction to Algebra A
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Introduction to Counting & Probability Self-Paced

Introduction to Counting & Probability
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Introduction to Number Theory
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Introduction to Algebra B Self-Paced

Introduction to Algebra B
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Intermediate: Grades 8-12

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Precalculus
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Olympiad Geometry
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Tuesday, May 27 - Nov 11
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Group Theory
Thursday, Jun 12 - Sep 11

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MATHCOUNTS/AMC 8 Basics
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MATHCOUNTS/AMC 8 Advanced
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AMC 10 Problem Series
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Tuesday, May 27 - Aug 12
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Thursday, May 22 - Jul 31

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Visit the pages linked for full schedule details for each of these programs!

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Physics 1: Mechanics
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Relativity
Mon, Tue, Wed & Thurs, Jun 23 - Jun 26 (meets every day of the week!)
0 replies
jlacosta
May 1, 2025
0 replies
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k i Adding contests to the Contest Collections
dcouchman   1
N Apr 5, 2023 by v_Enhance
Want to help AoPS remain a valuable Olympiad resource? Help us add contests to AoPS's Contest Collections.

Find instructions and a list of contests to add here: https://artofproblemsolving.com/community/c40244h1064480_contests_to_add
1 reply
dcouchman
Sep 9, 2019
v_Enhance
Apr 5, 2023
J
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k i Zero tolerance
ZetaX   49
N May 4, 2019 by NoDealsHere
Source: Use your common sense! (enough is enough)
Some users don't want to learn, some other simply ignore advises.
But please follow the following guideline:


To make it short: ALWAYS USE YOUR COMMON SENSE IF POSTING!
If you don't have common sense, don't post.


More specifically:

For new threads:


a) Good, meaningful title:
The title has to say what the problem is about in best way possible.
If that title occured already, it's definitely bad. And contest names aren't good either.
That's in fact a requirement for being able to search old problems.

Examples:
Bad titles:
- "Hard"/"Medium"/"Easy" (if you find it so cool how hard/easy it is, tell it in the post and use a title that tells us the problem)
- "Number Theory" (hey guy, guess why this forum's named that way¿ and is it the only such problem on earth¿)
- "Fibonacci" (there are millions of Fibonacci problems out there, all posted and named the same...)
- "Chinese TST 2003" (does this say anything about the problem¿)
Good titles:
- "On divisors of a³+2b³+4c³-6abc"
- "Number of solutions to x²+y²=6z²"
- "Fibonacci numbers are never squares"


b) Use search function:
Before posting a "new" problem spend at least two, better five, minutes to look if this problem was posted before. If it was, don't repost it. If you have anything important to say on topic, post it in one of the older threads.
If the thread is locked cause of this, use search function.

Update (by Amir Hossein). The best way to search for two keywords in AoPS is to input
[code]+"first keyword" +"second keyword"[/code]
so that any post containing both strings "first word" and "second form".


c) Good problem statement:
Some recent really bad post was:
[quote]$lim_{n\to 1}^{+\infty}\frac{1}{n}-lnn$[/quote]
It contains no question and no answer.
If you do this, too, you are on the best way to get your thread deleted. Write everything clearly, define where your variables come from (and define the "natural" numbers if used). Additionally read your post at least twice before submitting. After you sent it, read it again and use the Edit-Button if necessary to correct errors.


For answers to already existing threads:


d) Of any interest and with content:
Don't post things that are more trivial than completely obvious. For example, if the question is to solve $x^{3}+y^{3}=z^{3}$, do not answer with "$x=y=z=0$ is a solution" only. Either you post any kind of proof or at least something unexpected (like "$x=1337, y=481, z=42$ is the smallest solution). Someone that does not see that $x=y=z=0$ is a solution of the above without your post is completely wrong here, this is an IMO-level forum.
Similar, posting "I have solved this problem" but not posting anything else is not welcome; it even looks that you just want to show off what a genius you are.

e) Well written and checked answers:
Like c) for new threads, check your solutions at least twice for mistakes. And after sending, read it again and use the Edit-Button if necessary to correct errors.



To repeat it: ALWAYS USE YOUR COMMON SENSE IF POSTING!


Everything definitely out of range of common sense will be locked or deleted (exept for new users having less than about 42 posts, they are newbies and need/get some time to learn).

The above rules will be applied from next monday (5. march of 2007).
Feel free to discuss on this here.
49 replies
ZetaX
Feb 27, 2007
NoDealsHere
May 4, 2019
J
H
k Weird FTW game??
TheCoinNinja   3
N 2 hours ago by jlacosta
What is going on with this game??
As far as I can tell, this 10-problem, 45-second game has been sitting here with 1 of 1 players participating, and yet not started, for a long time. Also, I_am_a_penguin has a normal avatar, not the gray one.

Summary of the problem: This should not be possible. The game should have started when the user created it since it's just a one person game.
Page URL:aops.com/ftw/ftw
Expected behavior: The game should have either started or disappeared.
Frequency: 100%
Operating system(s): Windows 11
Browser(s), including version: Chrome and Firefox
3 replies
TheCoinNinja
Today at 1:20 AM
jlacosta
2 hours ago
J
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Bulgaria National Olympiad 1996
Jjesus   7
N 2 hours ago by reni_wee
Find all prime numbers $p,q$ for which $pq$ divides $(5^p-2^p)(5^q-2^q)$.
7 replies
Jjesus
Jun 10, 2020
reni_wee
2 hours ago
J
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Can't be power of 2
shobber   31
N 2 hours ago by LeYohan
Source: APMO 1998
Show that for any positive integers $a$ and $b$, $(36a+b)(a+36b)$ cannot be a power of $2$.
31 replies
shobber
Mar 17, 2006
LeYohan
2 hours ago
J
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k AoPS Report Bar
Svnshiin3-QTPI   5
N 2 hours ago by jlacosta
Hello there!
This is my first AoPS class, and I was wondering why my report bar is orange.
I have completed all of the Challenge homework problems, as well as the writing problems.
Is this because the writing problems have not been graded yet?
If not, are there any other assignments I need to complete?
Thanks.

(edit: resolved)
5 replies
Svnshiin3-QTPI
Today at 4:01 AM
jlacosta
2 hours ago
J
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Brilliant Problem
M11100111001Y1R   4
N 2 hours ago by IAmTheHazard
Source: Iran TST 2025 Test 3 Problem 3
Find all sequences \( (a_n) \) of natural numbers such that for every pair of natural numbers \( r \) and \( s \), the following inequality holds:
\[ \frac{1}{2} < \frac{\gcd(a_r, a_s)}{\gcd(r, s)} < 2 \]
4 replies
M11100111001Y1R
Yesterday at 7:28 AM
IAmTheHazard
2 hours ago
J
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Own made functional equation
Primeniyazidayi   1
N 2 hours ago by Primeniyazidayi
Source: own(probably)
Find all functions $f:R \rightarrow R$ such that $xf(x^2+2f(y)-yf(x))=f(x)^3-f(y)(f(x^2)-2f(x))$ for all $x,y \in \mathbb{R}$
1 reply
Primeniyazidayi
May 26, 2025
Primeniyazidayi
2 hours ago
J
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not fun equation
DottedCaculator   13
N 3 hours ago by Adywastaken
Source: USA TST 2024/6
Find all functions $f\colon\mathbb R\to\mathbb R$ such that for all real numbers $x$ and $y$,
\[f(xf(y))+f(y)=f(x+y)+f(xy).\]
Milan Haiman
13 replies
DottedCaculator
Jan 15, 2024
Adywastaken
3 hours ago
J
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Serbian selection contest for the IMO 2025 - P6
OgnjenTesic   12
N 4 hours ago by atdaotlohbh
Source: Serbian selection contest for the IMO 2025
For an $n \times n$ table filled with natural numbers, we say it is a divisor table if:
- the numbers in the $i$-th row are exactly all the divisors of some natural number $r_i$,
- the numbers in the $j$-th column are exactly all the divisors of some natural number $c_j$,
- $r_i \ne r_j$ for every $i \ne j$.

A prime number $p$ is given. Determine the smallest natural number $n$, divisible by $p$, such that there exists an $n \times n$ divisor table, or prove that such $n$ does not exist.

Proposed by Pavle Martinović
12 replies
OgnjenTesic
May 22, 2025
atdaotlohbh
4 hours ago
J
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Geometry with fix circle
falantrng   33
N 4 hours ago by zuat.e
Source: RMM 2018 Problem 6
Fix a circle $\Gamma$, a line $\ell$ to tangent $\Gamma$, and another circle $\Omega$ disjoint from $\ell$ such that $\Gamma$ and $\Omega$ lie on opposite sides of $\ell$. The tangents to $\Gamma$ from a variable point $X$ on $\Omega$ meet $\ell$ at $Y$ and $Z$. Prove that, as $X$ varies over $\Omega$, the circumcircle of $XYZ$ is tangent to two fixed circles.
33 replies
falantrng
Feb 25, 2018
zuat.e
4 hours ago
J
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USAMO 2001 Problem 2
MithsApprentice   54
N 4 hours ago by lpieleanu
Let $ABC$ be a triangle and let $\omega$ be its incircle. Denote by $D_1$ and $E_1$ the points where $\omega$ is tangent to sides $BC$ and $AC$, respectively. Denote by $D_2$ and $E_2$ the points on sides $BC$ and $AC$, respectively, such that $CD_2=BD_1$ and $CE_2=AE_1$, and denote by $P$ the point of intersection of segments $AD_2$ and $BE_2$. Circle $\omega$ intersects segment $AD_2$ at two points, the closer of which to the vertex $A$ is denoted by $Q$. Prove that $AQ=D_2P$.
54 replies
MithsApprentice
Sep 30, 2005
lpieleanu
4 hours ago
J
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German-Style System of Equations
Primeniyazidayi   1
N 5 hours ago by Primeniyazidayi
Source: German MO 2025 11/12 Day 1 P1
Solve the system of equations in $\mathbb{R}$

\begin{align*} \frac{a}{c} &= b-\sqrt{b}+c \\ \sqrt{\frac{a}{c}} &= \sqrt{b}+1 \\ \sqrt[4]{\frac{a}{c}} &=\sqrt[3]{b}-1 \end{align*}
1 reply
Primeniyazidayi
5 hours ago
Primeniyazidayi
5 hours ago
J
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gcd nt from switzerland
AshAuktober   5
N 5 hours ago by Siddharthmaybe
Source: Swiss 2025 Second Round
Let $a, b$ be positive integers. Prove that the expression
\[\frac{\gcd(a+b,ab)}{\gcd(a,b)}\]is always a positive integer, and determine all possible values it can take.
5 replies
AshAuktober
6 hours ago
Siddharthmaybe
5 hours ago
J
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Stamina XP decreasing?
Craftybutterfly   29
N Today at 3:11 AM by Craftybutterfly
Summary of the problem: Last night when I checked, alcumus said I had 4250 stamina XP which is more than other people. However, when I just checked, it said I only earned 3905 XP. What is wrong?
Page URL: Hall of Fame
Steps to reproduce:
1. Go to hall of fame
2. Scroll to stamina XP earned
Expected behavior: It should still say I earned 4250 XP
Frequency: 100%
Operating system(s): HP Elitebook
Browser(s), including version: Chrome
IMAGE
29 replies
Craftybutterfly
May 22, 2025
Craftybutterfly
Today at 3:11 AM
J
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Hide tag workaround
char0221   6
N Yesterday at 10:56 PM by jlacosta
Summary of the problem: When quoting a tip tag, hovering over it causes a glitch where the tip tag's inner contents are "stuck" below the quotes.
Page URL: Any community message boards.
Steps to reproduce:
1. Create a message.
2. Insert a quote.
3. Inside the quote, put a tip tag.
4. Submit/preview, then hover over the tip tag.
Expected behavior: Tip tag does not stay when mouse is removed.
Frequency: 100%
Operating system(s): macOS Sequoia
Browser(s), including version: Safari 18.4
Additional information:
IMAGE
Also, make sure that the quote+tip is last.
[quote=char0221]
Try to close me!
[/quote]
6 replies
char0221
May 26, 2025
jlacosta
Yesterday at 10:56 PM
J
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J
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k Question for users
BOOGA   3
N Sep 3, 2016 by Littlelachy
why in alcumus you can't go higher than a 100?i want to go higher.:)
3 replies
BOOGA
Sep 1, 2016
Littlelachy
Sep 3, 2016
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Question for users
G H J
Reveal topic tags
Alcumus
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BOOGA
599 posts
BOOGA
#1 h  Sep 1, 2016, 2:03 AM • 3 Y
Y by Thebeastmode, Adventure10, Mango247
why in alcumus you can't go higher than a 100?i want to go higher.:)
Z Y
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noah_liu
179 posts
noah_liu
#3 h  Sep 1, 2016, 2:33 AM • 1 Y
Y by Adventure10
When you get to 100, that pretty much means you have fully mastered the topic.
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relay400
3222 posts
relay400
#4 h  Sep 1, 2016, 2:35 AM • 3 Y
Y by pv2014, hockey10, Adventure10
Think about it as 100%.
Z Y
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Littlelachy
934 posts
Littlelachy
#7 h  Sep 3, 2016, 1:15 PM • 1 Y
Y by Adventure10
BOOGA wrote:
why in alcumus you can't go higher than a 100?i want to go higher.:)

100=100%
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a