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k a April Highlights and 2025 AoPS Online Class Information
jlacosta   0
Apr 2, 2025
Spring is in full swing and summer is right around the corner, what are your plans? At AoPS Online our schedule has new classes starting now through July, so be sure to keep your skills sharp and be prepared for the Fall school year! Check out the schedule of upcoming classes below.

WOOT early bird pricing is in effect, don’t miss out! If you took MathWOOT Level 2 last year, no worries, it is all new problems this year! Our Worldwide Online Olympiad Training program is for high school level competitors. AoPS designed these courses to help our top students get the deep focus they need to succeed in their specific competition goals. Check out the details at this link for all our WOOT programs in math, computer science, chemistry, and physics.

Looking for summer camps in math and language arts? Be sure to check out the video-based summer camps offered at the Virtual Campus that are 2- to 4-weeks in duration. 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 events:
[list][*]April 3rd (Webinar), 4pm PT/7:00pm ET, Learning with AoPS: Perspectives from a Parent, Math Camp Instructor, and University Professor
[*]April 8th (Math Jam), 4:30pm PT/7:30pm ET, 2025 MATHCOUNTS State Discussion
April 9th (Webinar), 4:00pm PT/7:00pm ET, Learn about Video-based Summer Camps at the Virtual Campus
[*]April 10th (Math Jam), 4:30pm PT/7:30pm ET, 2025 MathILy and MathILy-Er Math Jam: Multibackwards Numbers
[*]April 22nd (Webinar), 4:00pm PT/7:00pm ET, Competitive Programming at AoPS (USACO).[/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

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Introduction to Algebra A
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0 replies
jlacosta
Apr 2, 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
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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
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Number theory
falantrng   38
N an hour ago by Ilikeminecraft
Source: RMM 2018 D2 P4
Let $a,b,c,d$ be positive integers such that $ad \neq bc$ and $gcd(a,b,c,d)=1$. Let $S$ be the set of values attained by $\gcd(an+b,cn+d)$ as $n$ runs through the positive integers. Show that $S$ is the set of all positive divisors of some positive integer.
38 replies
falantrng
Feb 25, 2018
Ilikeminecraft
an hour ago
J
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USAMO 2001 Problem 5
MithsApprentice   23
N an hour ago by Ilikeminecraft
Let $S$ be a set of integers (not necessarily positive) such that

(a) there exist $a,b \in S$ with $\gcd(a,b)=\gcd(a-2,b-2)=1$;
(b) if $x$ and $y$ are elements of $S$ (possibly equal), then $x^2-y$ also belongs to $S$.

Prove that $S$ is the set of all integers.
23 replies
MithsApprentice
Sep 30, 2005
Ilikeminecraft
an hour ago
J
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IMO 2016 Shortlist, N6
dangerousliri   67
N an hour ago by Ilikeminecraft
Denote by $\mathbb{N}$ the set of all positive integers. Find all functions $f:\mathbb{N}\rightarrow \mathbb{N}$ such that for all positive integers $m$ and $n$, the integer $f(m)+f(n)-mn$ is nonzero and divides $mf(m)+nf(n)$.

Proposed by Dorlir Ahmeti, Albania
67 replies
dangerousliri
Jul 19, 2017
Ilikeminecraft
an hour ago
J
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IMO ShortList 1998, number theory problem 1
orl   54
N an hour ago by Ilikeminecraft
Source: IMO ShortList 1998, number theory problem 1
Determine all pairs $(x,y)$ of positive integers such that $x^{2}y+x+y$ is divisible by $xy^{2}+y+7$.
54 replies
orl
Oct 22, 2004
Ilikeminecraft
an hour ago
J
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IMO Shortlist 2011, Number Theory 3
orl   47
N an hour ago by Ilikeminecraft
Source: IMO Shortlist 2011, Number Theory 3
Let $n \geq 1$ be an odd integer. Determine all functions $f$ from the set of integers to itself, such that for all integers $x$ and $y$ the difference $f(x)-f(y)$ divides $x^n-y^n.$

Proposed by Mihai Baluna, Romania
47 replies
orl
Jul 11, 2012
Ilikeminecraft
an hour ago
J
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IMO ShortList 2002, number theory problem 6
orl   30
N an hour ago by Ilikeminecraft
Source: IMO ShortList 2002, number theory problem 6
Find all pairs of positive integers $m,n\geq3$ for which there exist infinitely many positive integers $a$ such that \[ \frac{a^m+a-1}{a^n+a^2-1} \] is itself an integer.

Laurentiu Panaitopol, Romania
30 replies
orl
Sep 28, 2004
Ilikeminecraft
an hour ago
J
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Euclid NT
Taco12   12
N an hour ago by Ilikeminecraft
Source: 2023 Fall TJ Proof TST, Problem 4
Find all pairs of positive integers $(a,b)$ such that \[ a^2b-1 \mid ab^3-1. \]
Calvin Wang
12 replies
Taco12
Oct 6, 2023
Ilikeminecraft
an hour ago
J
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A=b
k2c901_1   87
N an hour ago by Ilikeminecraft
Source: Taiwan 1st TST 2006, 1st day, problem 3
Let $a$, $b$ be positive integers such that $b^n+n$ is a multiple of $a^n+n$ for all positive integers $n$. Prove that $a=b$.

Proposed by Mohsen Jamali, Iran
87 replies
k2c901_1
Mar 29, 2006
Ilikeminecraft
an hour ago
J
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Floor of square root
v_Enhance   43
N an hour ago by Ilikeminecraft
Source: APMO 2013, Problem 2
Determine all positive integers $n$ for which $\dfrac{n^2+1}{[\sqrt{n}]^2+2}$ is an integer. Here $[r]$ denotes the greatest integer less than or equal to $r$.
43 replies
v_Enhance
May 3, 2013
Ilikeminecraft
an hour ago
J
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Pair of multiples
Jalil_Huseynov   62
N an hour ago by Ilikeminecraft
Source: APMO 2022 P1
Find all pairs $(a,b)$ of positive integers such that $a^3$ is multiple of $b^2$ and $b-1$ is multiple of $a-1$.
62 replies
1 viewing
Jalil_Huseynov
May 17, 2022
Ilikeminecraft
an hour ago
J
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Introducing myself at AoPS, and what's your magic wand?
asuth_asuth   939
N 2 hours ago by bpan2021
Hi!

I'm Andrew Sutherland. I'm the new Chief Product Officer at AoPS. As you may have read, Richard is retiring and Ben Kornell and I are working together to lead the company now. I'm leading all the software and digital stuff at AoPS. I just wanted to say hello and introduce myself! I'm really excited to be part of the special community that is AoPS.

Previously, I founded Quizlet as a 15-year-old high school student. I did Course 6 at MIT and then left to lead Quizlet full-time for a total of 14 years. I took a few years off and now I'm doing AoPS! I wrote more about all that on my blog: https://asuth.com/im-joining-aops

I have a question for all of you. If you could wave a magic wand, and change anything about AoPS, what would it be? All suggestions welcome! Thank you.
939 replies
1 viewing
asuth_asuth
Mar 30, 2025
bpan2021
2 hours ago
J
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k Internet bug
MmathB   8
N Yesterday at 9:38 PM by MathDolphin95
I am trying to post topics in a forum, but every time I try to post it asks me to check my internet even though the signal is strong can somebody tell me what's going on
8 replies
MmathB
Wednesday at 5:41 PM
MathDolphin95
Yesterday at 9:38 PM
J
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Error in forum
Speedysolver1   1
N Apr 23, 2025 by Demetri
Will put video
1 reply
Speedysolver1
Apr 23, 2025
Demetri
Apr 23, 2025
J
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k Alcumus Error
AtlantisHSK2   4
N Apr 22, 2025 by jlacosta
Hi I've been doing pre 2 (I'm almost done), however I am having a problem with the alcumus that is integrated into the program. I have finished these alcumus sections well over 3 times, but after a few days they display that they're unfinished, I was wondering whether this was a bug and if there is some way to fix it.
4 replies
AtlantisHSK2
Apr 22, 2025
jlacosta
Apr 22, 2025
J
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J
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k Where to find archived PMs?
Yolandayu   3
N Apr 2, 2025 by Yolandayu
Hi! I didn't know where this should go, so I put it in site support. I am desperate to find where my archived PMs are! I accidentally archived one, because I thought the button was for bookmarking. Could someone please tell me? Thanks!
3 replies
Yolandayu
Apr 2, 2025
Yolandayu
Apr 2, 2025
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Where to find archived PMs?
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Reveal topic tags
pms
Support
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Yolandayu
558 posts
Yolandayu
#1 h  Apr 2, 2025, 9:06 PM
Y by
Hi! I didn't know where this should go, so I put it in site support. I am desperate to find where my archived PMs are! I accidentally archived one, because I thought the button was for bookmarking. Could someone please tell me? Thanks!
Z Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
bpan2021
2617 posts
bpan2021
#2 h  Apr 2, 2025, 9:09 PM
Y by
Hello!
In your Private Messages page, you should find a View Archived Messages button on the top right, in a light blue bar. Here's the direct link to your Archived Private Messages.
This post has been edited 1 time. Last edited by bpan2021, Apr 2, 2025, 9:09 PM
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LostInBali
1905 posts
LostInBali
#3 h  Apr 2, 2025, 9:10 PM
Y by
Nevermind, sniped by bpan2021.
Thank you very much.

Hello,
Please click here to see your archived messages:
https://artofproblemsolving.com/community/my-messages-archive
This post has been edited 1 time. Last edited by LostInBali, Apr 2, 2025, 9:10 PM
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Yolandayu
558 posts
Yolandayu
#4 h  Apr 2, 2025, 9:18 PM • 1 Y
Y by LostInBali
Thanks so much! I got to it!
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