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H
k a April Highlights and 2025 AoPS Online Class Information
jlacosta   0
Yesterday at 3:18 PM
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.

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0 replies
jlacosta
Yesterday at 3:18 PM
0 replies
J
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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
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Darkmode
tyrantfire4   4
N 21 minutes ago by bpan2021
How do you turn on dark mode
I've looked everywhere
I have Chrome and a fire tablet
4 replies
tyrantfire4
an hour ago
bpan2021
21 minutes ago
J
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Introducing myself at AoPS, and what's your magic wand?
asuth_asuth   432
N an hour ago by MathPerson12321
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.
432 replies
+1 w
asuth_asuth
Mar 30, 2025
MathPerson12321
an hour ago
J
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Fneqn or Realpoly?
Mathandski   1
N 2 hours ago by Mathandski
Source: India, not sure which year. Found in OTIS pset
Find all polynomials $P$ with real coefficients obeying
\[P(x) P(x+1) = P(x^2 + x + 1)\]for all real numbers $x$.
1 reply
Mathandski
2 hours ago
Mathandski
2 hours ago
J
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D1010 : How it is possible ?
Dattier   14
N 2 hours ago by ehuseyinyigit
Source: les dattes à Dattier
Is it true that$$\forall n \in \mathbb N^*, (24^n \times B \mod A) \mod 2 = 0 $$?

A=1728400904217815186787639216753921417860004366580219212750904
024377969478249664644267971025952530803647043121025959018172048
336953969062151534282052863307398281681465366665810775710867856
720572225880311472925624694183944650261079955759251769111321319
421445397848518597584590900951222557860592579005088853698315463
815905425095325508106272375728975

B=2275643401548081847207782760491442295266487354750527085289354
965376765188468052271190172787064418854789322484305145310707614
546573398182642923893780527037224143380886260467760991228567577
953725945090125797351518670892779468968705801340068681556238850
340398780828104506916965606659768601942798676554332768254089685
307970609932846902
14 replies
Dattier
Mar 10, 2025
ehuseyinyigit
2 hours ago
J
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n=y^2+108
Havu   4
N 2 hours ago by MathPerson12321
Given the positive integer $n = y^2 + 108$ where $y \in \mathbb{N}$.
Prove that $n$ cannot be a perfect cube of a positive integer.
4 replies
Havu
3 hours ago
MathPerson12321
2 hours ago
J
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iran tst 2018 geometry
Etemadi   10
N 3 hours ago by amirhsz
Source: Iranian TST 2018, second exam day 2, problem 5
Let $\omega$ be the circumcircle of isosceles triangle $ABC$ ($AB=AC$). Points $P$ and $Q$ lie on $\omega$ and $BC$ respectively such that $AP=AQ$ .$AP$ and $BC$ intersect at $R$. Prove that the tangents from $B$ and $C$ to the incircle of $\triangle AQR$ (different from $BC$) are concurrent on $\omega$.

Proposed by Ali Zamani, Hooman Fattahi
10 replies
Etemadi
Apr 17, 2018
amirhsz
3 hours ago
J
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high school maths
aothatday   1
N 3 hours ago by waterbottle432
Source: my creation
find $f:\mathbb{R} \rightarrow \mathbb{R}$ such that:
$(x-y)(f(x)+f(y)) \leq f(x^2-y^2)$
1 reply
aothatday
5 hours ago
waterbottle432
3 hours ago
J
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Can't search in PMs
ChaitraliKA   11
N 4 hours ago by ChaitraliKA
Summary of the problem: searching literally anything doesn't give any results
Page URL: https://artofproblemsolving.com/community/search-private
Steps to reproduce:
1. Search literally anything!!! Any key words that you know are obviously present in your PMs. It does not give any search results.
Expected behavior: it should give search results similar to searching in forums
Frequency: every time
Browser(s), including version: chrome
Additional information: I tried on multiple devices
11 replies
ChaitraliKA
Yesterday at 1:04 PM
ChaitraliKA
4 hours ago
J
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Coaxial circles related to Gergon point
Headhunter   1
N 4 hours ago by internationalnick123456
Source: I tried but can't find the source...
Hi, everyone.

In $\triangle$$ABC$, $Ge$ is the Gergon point and the incircle $(I)$ touch $BC$, $CA$, $AB$ at $D$, $E$, $F$ respectively.
Let the circumcircles of $\triangle IDGe$, $\triangle IEGe$, $\triangle IFGe$ be $O_{1}$ , $O_{2}$ , $O_{3}$ respectively.

Reflect $O_{1}$ in $ID$ and then we get the circle $O'_{1}$
Reflect $O_{2}$ in $IE$ and then the circle $O'_{2}$
Reflect $O_{3}$ in $IF$ and then the circle $O'_{3}$

Prove that $O'_{1}$ , $O'_{2}$ , $O'_{3}$ are coaxial.
1 reply
Headhunter
Today at 2:48 AM
internationalnick123456
4 hours ago
J
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Something nice
KhuongTrang   25
N 4 hours ago by KhuongTrang
Source: own
Problem. Given $a,b,c$ be non-negative real numbers such that $ab+bc+ca=1.$ Prove that

$$\sqrt{a+1}+\sqrt{b+1}+\sqrt{c+1}\le 1+2\sqrt{a+b+c+abc}.$$
25 replies
KhuongTrang
Nov 1, 2023
KhuongTrang
4 hours ago
J
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Inequality from China
sqing   1
N 4 hours ago by SunnyEvan
Source: lemondian(https://kuing.cjhb.site/thread-13667-1-1.html)
Let $x\in (0,\frac{\pi}{2}) . $ Prove that $$tanx\ge x^k$$Where $ k=1,2,3,4.$
1 reply
sqing
Today at 1:11 PM
SunnyEvan
4 hours ago
J
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Burak0609
Burak0609   0
5 hours ago
So $b=x+y+z$ $x^3+a=-3y-3z$ $P(t)=t^3-3t+a-3b\implies x+y+z=0$ from vieta $x^3+a=-3y-3z,y^3+a=-3x-3z\implies x^2+xy+y^2=3\implies y^2+xy+(x^2-3)=0\implies \Delta\ge 0 \implies 12\ge 3x^2 \implies x\in [-2,2]$. Notice in similar fashion we get $y\in [-2,2] , z\in [-2,2]$, also its easy to observe that none of $\{x,y,z\} \in \{-2,2,0\}$. So we have$\boxed{a \in (-2,2)-\{0\}}$
0 replies
Burak0609
5 hours ago
0 replies
J
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Two submit buttons?
Craftybutterfly   6
N 5 hours ago by Craftybutterfly
Summary of the problem: on phones, there are two submit response buttons
Page URL: any topic
Steps to reproduce:
1.open a topic
2. press reply
3.you see it
...
Expected behavior: there’s supposed to be one submit button
Frequency: 100%
Operating system(s): iPhone XR
Browser(s), including version: chrome latest version
Additional information: https://drive.google.com/file/d/1kFakLeI1aXoPAQHAwhVneXLWg6OaCaCv/view?usp=drivesdk
6 replies
Craftybutterfly
Today at 12:49 AM
Craftybutterfly
5 hours ago
J
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Problem 1 IMO 2005 (Day 1)
Valentin Vornicu   92
N 5 hours ago by Baimukh
Six points are chosen on the sides of an equilateral triangle $ABC$: $A_1$, $A_2$ on $BC$, $B_1$, $B_2$ on $CA$ and $C_1$, $C_2$ on $AB$, such that they are the vertices of a convex hexagon $A_1A_2B_1B_2C_1C_2$ with equal side lengths.

Prove that the lines $A_1B_2$, $B_1C_2$ and $C_1A_2$ are concurrent.

Bogdan Enescu, Romania
92 replies
Valentin Vornicu
Jul 13, 2005
Baimukh
5 hours ago
J
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J
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k They added something new on community!!!!
jb2015007   7
N Mar 28, 2025 by eg4334
They added something new on community!!!!
7 replies
jb2015007
Mar 28, 2025
eg4334
Mar 28, 2025
J
They added something new on community!!!!
G H J
Reveal topic tags
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jb2015007
1773 posts
jb2015007
#1 h  Mar 28, 2025, 9:23 PM
Y by
They added something new on community!!!!
Z Y
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twang2015
297 posts
twang2015
#3 h  Mar 28, 2025, 9:25 PM
Y by
ooookayyy
Z Y
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CurlyFalcon55
410 posts
CurlyFalcon55
#4 h  Mar 28, 2025, 9:25 PM
Y by
Okayyyyyy…
and soooo…?
Z Y
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jb2015007
1773 posts
jb2015007
#5 h  Mar 28, 2025, 9:28 PM
Y by
nth js wanted to point it out sry
Z Y
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jb2015007
1773 posts
jb2015007
#6 h  Mar 28, 2025, 9:29 PM
Y by
WOAHHH NSATO IS READING THIS RN
Z Y
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CurlyFalcon55
410 posts
CurlyFalcon55
#7 h  Mar 28, 2025, 9:35 PM
Y by
What's the "something"?
Z Y
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pingpongmerrily
3527 posts
pingpongmerrily
#8 h  Mar 28, 2025, 9:36 PM
Y by
There's a new "NEWS" header with some new sections
Z Y
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eg4334
617 posts
eg4334
#9 h  Mar 28, 2025, 9:49 PM
Y by
where is blogroll
please fix this
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a