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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]
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All classes run 7:30pm-8:45pm ET/4:30pm - 5:45pm PT unless otherwise noted.

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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
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
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USA(J)MO Statistics Out
BS2012   40
N a few seconds ago by joebub56
Source: MAA edvistas page
https://maa.edvistas.com/eduview/report.aspx?view=1561&mode=6
who were the 2 usamo perfects
40 replies
+2 w
BS2012
Yesterday at 10:07 PM
joebub56
a few seconds ago
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0 on jmo
Rong0625   49
N 6 minutes ago by InftyByond
How many people actually get a flat 0/42 on jmo? I took it for the first time this year and I had never done oly math before so I really only had 2 weeks to figure it out since I didn’t think I would qual. I went in not expecting much but I didn’t think I wouldn’t be able to get ANYTHING. So I’m pretty sure I got 0/42 (unless i get pity points for writing incorrect solutions). Is that bad, am I sped, and should I be embarrassed? Or do other people actually also get 0?
49 replies
Rong0625
Mar 21, 2025
InftyByond
6 minutes ago
J
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9 Fun Proof Endings
elasticwealth   35
N 39 minutes ago by BS2012
It seems like AOPS is going through a stressful phase right now.

Let's lighten the mood by voting on the best proof endings!
35 replies
elasticwealth
Today at 12:26 AM
BS2012
39 minutes ago
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MOP Emails Out! (not clickbait)
Mathandski   79
N an hour ago by KnowingAnt
What an emotional roller coaster the past 34 days have been.

Congrats to all that qualified!
79 replies
+2 w
Mathandski
Apr 22, 2025
KnowingAnt
an hour ago
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Japan MO finals 2023 NT
EVKV   3
N 2 hours ago by L13832
Source: Japan MO finals 2023
Determine all positive integers $n$ such that $n$ divides $\phi(n)^{d(n)}+1$ but $d(n)^5$ does not divide $n^{\phi(n)}-1$.
3 replies
1 viewing
EVKV
3 hours ago
L13832
2 hours ago
J
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tangential trapezoid with 2 right angles
parmenides51   1
N 2 hours ago by vanstraelen
Source: 2002 Germany R4 11.6 https://artofproblemsolving.com/community/c3208025_
A trapezoid $ABCD$ with right angles at $A$ and $D$ has an inscribed circle with center $M$ and radius $r$. Let the lengths of the parallel sides $\overline{AB}$ and $\overline{CD}$ be $a$ and $c$, and the intersection of the diagonals $\overline{AC}$ and $\overline{BD}$ be $S$.
1. Prove that the perpendicular from $S$ to one of the trapezoid sides has the length $r$.
2. Determine the distance between $M$ and $S$ as a function of $r$ and $a$.
1 reply
parmenides51
Sep 25, 2024
vanstraelen
2 hours ago
J
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Neuberg Cubic leads to fixed point
YaoAOPS   1
N 3 hours ago by huoxy1623
Source: own
Let $P$ be a point on the Neuberg cubic. Show that as $P$ varies, the Nine Point Circle of the antipedal triangle of $P$ goes through a fixed point.
1 reply
YaoAOPS
4 hours ago
huoxy1623
3 hours ago
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Prove that 4p-3 is a square - Iran NMO 2005 - Problem1
sororak   21
N 3 hours ago by Maximilian113
Let $n,p>1$ be positive integers and $p$ be prime. We know that $n|p-1$ and $p|n^3-1$. Prove that $4p-3$ is a perfect square.
21 replies
sororak
Sep 21, 2010
Maximilian113
3 hours ago
J
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Existence of m and n
shobber   6
N 4 hours ago by Rayanelba
Source: Pan African 2004
Do there exist positive integers $m$ and $n$ such that:
\[ 3n^2+3n+7=m^3 \]
6 replies
shobber
Oct 4, 2005
Rayanelba
4 hours ago
J
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Geometry Handout is finally done!
SimplisticFormulas   1
N 4 hours ago by AshAuktober
If there’s any typo or problem you think will be a nice addition, do send here!
handout, geometry
1 reply
SimplisticFormulas
4 hours ago
AshAuktober
4 hours ago
J
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Finding all integers with a divisibility condition
Tintarn   13
N 4 hours ago by EVKV
Source: Germany 2020, Problem 4
Determine all positive integers $n$ for which there exists a positive integer $d$ with the property that $n$ is divisible by $d$ and $n^2+d^2$ is divisible by $d^2n+1$.
13 replies
Tintarn
Jun 22, 2020
EVKV
4 hours ago
J
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lots of perpendicular
m4thbl3nd3r   0
4 hours ago
Let $\omega$ be the circumcircle of a non-isosceles triangle $ABC$ and $SA$ be a tangent line to $\omega$ ($S\in BC$). Let $AD\perp BC,I$ be midpoint of $BC$ and $IQ\perp AB,AH\perp SO,AH\cap QD=K$. Prove that $SO\parallel CK$
0 replies
m4thbl3nd3r
4 hours ago
0 replies
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p is divisible by 2003
shobber   8
N 4 hours ago by Rayanelba
Source: Pan African 2000
Let $p$ and $q$ be coprime positive integers such that:
\[ \dfrac{p}{q}=1-\frac12+\frac13-\frac14 \cdots -\dfrac{1}{1334}+\dfrac{1}{1335} \]
Prove $p$ is divisible by 2003.
8 replies
shobber
Oct 3, 2005
Rayanelba
4 hours ago
J
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Funny Diophantine
Taco12   21
N 4 hours ago by emmarose55
Source: 2023 RMM, Problem 1
Determine all prime numbers $p$ and all positive integers $x$ and $y$ satisfying $$x^3+y^3=p(xy+p).$$
21 replies
Taco12
Mar 1, 2023
emmarose55
4 hours ago
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USAMO Scores
KadenC2026   3
N Apr 12, 2025 by CatCatHead
Has anyone got their scores back for USAMO? I tried checking in the AMC portal and it's not out for me yet.
3 replies
KadenC2026
Apr 11, 2025
CatCatHead
Apr 12, 2025
J
USAMO Scores
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Reveal topic tags
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KadenC2026
24 posts
KadenC2026
#1 h  Apr 11, 2025, 10:05 PM
Y by
Has anyone got their scores back for USAMO? I tried checking in the AMC portal and it's not out for me yet.
Z K Y
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YauYauFilter
5 posts
YauYauFilter
#2 h  Apr 11, 2025, 11:56 PM
Y by
No. I think we'll get them around 4/25.
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imagien_bad
58 posts
imagien_bad
#3 h  Apr 12, 2025, 12:41 AM
Y by
YauYauFilter wrote:
No. I think we'll get them around 4/25.

what makes you say that?
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CatCatHead
32 posts
CatCatHead
#4 h  Apr 12, 2025, 5:37 AM
Y by
imagien_bad wrote:
YauYauFilter wrote:
No. I think we'll get them around 4/25.

what makes you say that?

last year 4/19 mop letter and 4/25 released score
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