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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
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April 9th (Webinar), 4:00pm PT/7:00pm ET, Learn about Video-based Summer Camps at the Virtual Campus
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[*]April 22nd (Webinar), 4:00pm PT/7:00pm ET, Competitive Programming at AoPS (USACO).[/list]
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0 replies
jlacosta
Apr 2, 2025
0 replies
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
Nationalist Combo
blacksheep2003   15
N 5 minutes ago by cj13609517288
Source: USEMO 2019 Problem 5
Let $\mathcal{P}$ be a regular polygon, and let $\mathcal{V}$ be its set of vertices. Each point in $\mathcal{V}$ is colored red, white, or blue. A subset of $\mathcal{V}$ is patriotic if it contains an equal number of points of each color, and a side of $\mathcal{P}$ is dazzling if its endpoints are of different colors.

Suppose that $\mathcal{V}$ is patriotic and the number of dazzling edges of $\mathcal{P}$ is even. Prove that there exists a line, not passing through any point in $\mathcal{V}$, dividing $\mathcal{V}$ into two nonempty patriotic subsets.

Ankan Bhattacharya
15 replies
blacksheep2003
May 24, 2020
cj13609517288
5 minutes ago
Concurrency with 10 lines
oVlad   1
N 18 minutes ago by kokcio
Source: Romania EGMO TST 2017 Day 1 P1
Consider five points on a circle. For every three of them, we draw the perpendicular from the centroid of the triangle they determine to the line through the remaining two points. Prove that the ten lines thus formed are concurrent.
1 reply
oVlad
4 hours ago
kokcio
18 minutes ago
Advanced topics in Inequalities
va2010   21
N 21 minutes ago by Novmath
So a while ago, I compiled some tricks on inequalities. You are welcome to post solutions below!
21 replies
va2010
Mar 7, 2015
Novmath
21 minutes ago
GCD of a sequence
oVlad   1
N 27 minutes ago by kokcio
Source: Romania EGMO TST 2017 Day 1 P2
Determine all pairs $(a,b)$ of positive integers with the following property: all of the terms of the sequence $(a^n+b^n+1)_{n\geqslant 1}$ have a greatest common divisor $d>1.$
1 reply
+2 w
oVlad
4 hours ago
kokcio
27 minutes ago
No more topics!
Zero tolerance
G H J
G H BBookmark kLocked kLocked NReply
Source: Use your common sense! (enough is enough)
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jlordhe
1965 posts
#36 • 10 Y
Y by Amir Hossein, Purple_Planet, pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, Mango247, cubres
LoveMaths26102003 wrote:
Moderators are the ones with green usernames??

Blue usernames are site admins, red usernames are forum admins.
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Mathlete2017
3233 posts
#37 • 8 Y
Y by pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, Mango247, cubres
jlordhe wrote:
LoveMaths26102003 wrote:
Moderators are the ones with green usernames??

Blue usernames are site admins, red usernames are forum admins.
Blue usernames with the X at the beginning, that is.
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RopuToran
609 posts
#38 • 7 Y
Y by pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, cubres
Question: Is that OK when posting a geometry problem without any figure ?
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adityaguharoy
4655 posts
#39 • 8 Y
Y by pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, Mango247, cubres
RopuToran wrote:
Question: Is that OK when posting a geometry problem without any figure ?

Yes that's perfectly fine. In fact the P6 of IMO 2018 had no figure in the official statement of the problem.
This post has been edited 1 time. Last edited by adityaguharoy, Sep 15, 2018, 12:09 PM
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RopuToran
609 posts
#40 • 9 Y
Y by Purple_Planet, pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, Mango247, cubres
In IMO the problem was checked for several times :) But here, posting a figure will help other people know if the statement are true quickly.
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adityaguharoy
4655 posts
#41 • 7 Y
Y by pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, cubres
RopuToran wrote:
In IMO the problem was checked for several times :) But here, posting a figure will help other people know if the statement are true quickly.

Although I agree that a picture can be worth more than a thousand words, but if someone can give a good description of what's going on in the problem then there is no need to add a picture. But if someone thinks that the problem will be easier to understand from the figure then adding a figure can be golden.
In other words, it is not necessary to add a figure, but if you want you can add one.
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stronto
607 posts
#43 • 30 Y
Y by govind7701, khan.academy, Arthur., SolemnSolver, integrated_JRC, Kayak, MathematicalPhysicist, ywq233, Wizard_32, OliverA, Varuneshwara, AopsUser101, Purple_Planet, Inconsistent, pog, spicemax, samrocksnature, Siddharth03, suvamkonar, jhu08, megarnie, snap7822, ImSh95, aidan0626, Adventure10, Mango247, idkk, NicoN9, kiyoras_2001, cubres
I want to disagree with (a), sometimes titles like "Chinese TST 2003, Problem 1" are useful, as it allows other users who took the test to find discussion threads easier.

I personally dislike 'creative titles' because they sometimes spoil the problem. Calling 2018 AIME II #14 "Projective Fun" would be a prime example, as it describes a method people would use to solve the problem.
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hydrohelium
245 posts
#45 • 14 Y
Y by khan.academy, integrated_JRC, Purple_Planet, pog, samrocksnature, Siddharth03, jhu08, megarnie, ImSh95, player01, Adventure10, Mango247, Mango247, cubres
Dear Maththinkers,

I too agree with ZetaX but I believe contest name are good titles.
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khan.academy
634 posts
#46 • 9 Y
Y by hydrohelium, Purple_Planet, pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, cubres
hydrohelium wrote:
Dear Maththinkers,

I too agree with ZetaX but I believe contest name are good titles.

Yeah, I think the same.
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FedeX333X
792 posts
#47 • 9 Y
Y by OliverA, Purple_Planet, pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, cubres
@above You can already specify that in "source".
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Danielmath12
34 posts
#49 • 10 Y
Y by hydrohelium, Purple_Planet, pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, Mango247, cubres
I do agree with ZetaX, but I also agree with @above2 & @above3.
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mathroyal
443 posts
#54 • 9 Y
Y by Electro__Wizard, Purple_Planet, pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, cubres
But, there are a lot of questions of contests that are not from the moderators of admins. Then, how can we post the problem in contest?(like amcs)
This post has been edited 1 time. Last edited by mathroyal, Feb 25, 2019, 3:16 PM
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skywalker321
1358 posts
#55 • 12 Y
Y by AlastorMoody, Danielmath12, Purple_Planet, v4913, pog, samrocksnature, jhu08, megarnie, ImSh95, Adventure10, Mango247, cubres
why would you post amc questions in hso when it says olympiads in it hmm
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hashtagmath
1601 posts
#56 • 19 Y
Y by AlastorMoody, Dr_Vex, Professor-Mom, Purple_Planet, nicarmt, v4913, pog, Bradygho, sotpidot, HamstPan38825, samrocksnature, megarnie, jhu08, EZmath2006, ImSh95, aidan0626, Adventure10, rty, cubres
cause they want to get their HSO posts up. to look like they're smart.
This post has been edited 1 time. Last edited by hashtagmath, May 1, 2019, 10:20 PM
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NoDealsHere
1599 posts
#57 • 15 Y
Y by RishiNandha_M, Purple_Planet, pog, crazyeyemoody907, sotpidot, samrocksnature, jhu08, megarnie, Scooby07, BunnyAoPS, ImSh95, aidan0626, Adventure10, QueenArwen, cubres
skywalker321 wrote:
why would you post amc questions in hso when it says olympiads in it hmm

no common sense
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