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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)!

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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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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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Functional Equation
AnhQuang_67   5
N an hour ago by jasperE3
Find all functions $f: \mathbb{R} \to \mathbb{R}$ satisfying $$2\cdot f\Big(\dfrac{-xy}{2}+f(x+y)\Big)=xf(y)+yf(x), \forall x, y \in \mathbb{R} $$
5 replies
AnhQuang_67
Yesterday at 4:50 PM
jasperE3
an hour ago
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Special line through antipodal
Phorphyrion   8
N an hour ago by optimusprime154
Source: 2025 Israel TST Test 1 P2
Triangle $\triangle ABC$ is inscribed in circle $\Omega$. Let $I$ denote its incenter and $I_A$ its $A$-excenter. Let $N$ denote the midpoint of arc $BAC$. Line $NI_A$ meets $\Omega$ a second time at $T$. The perpendicular to $AI$ at $I$ meets sides $AC$ and $AB$ at $E$ and $F$ respectively. The circumcircle of $\triangle BFT$ meets $BI_A$ a second time at $P$, and the circumcircle of $\triangle CET$ meets $CI_A$ a second time at $Q$. Prove that $PQ$ passes through the antipodal to $A$ on $\Omega$.
8 replies
Phorphyrion
Oct 28, 2024
optimusprime154
an hour ago
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PoP+Parallel
Solilin   1
N 2 hours ago by sansgankrsngupta
Source: Titu Andreescu, Lemmas in Olympiad Geometry
Let ABC be a triangle and let D, E, F be the feet of the altitudes, with D on BC, E on CA, and F on AB. Let the parallel through D to EF meet AB at X and AC at Y. Let T be the intersection of EF with BC and let M be the midpoint of side BC. Prove that the points T, M, X, Y are concyclic.
1 reply
Solilin
2 hours ago
sansgankrsngupta
2 hours ago
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gcd of coefficients of polynomial
QueenArwen   2
N 2 hours ago by AshAuktober
Source: 46th International Tournament of Towns, Senior O-Level P5, Spring 2025
Given a polynomial with integer coefficients, which has at least one integer root. The greatest common divisor of all its integer roots equals $1$. Prove that if the leading coefficient of the polynomial equals $1$ then the greatest common divisor of the other coefficients also equals $1$.
2 replies
1 viewing
QueenArwen
Mar 11, 2025
AshAuktober
2 hours ago
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Another config geo with concurrent lines
a_507_bc   15
N 2 hours ago by E50
Source: BMO SL 2023 G5
Let $ABC$ be a triangle with circumcenter $O$. Point $X$ is the intersection of the parallel line from $O$ to $AB$ with the perpendicular line to $AC$ from $C$. Let $Y$ be the point where the external bisector of $\angle BXC$ intersects with $AC$. Let $K$ be the projection of $X$ onto $BY$. Prove that the lines $AK, XO, BC$ have a common point.
15 replies
a_507_bc
May 3, 2024
E50
2 hours ago
J
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Dwarves at the river
Experia   1
N 2 hours ago by Radin_
Source: Stage PreIMO 2018 - Italy
There are $100$ dwarves, whose weigths are $1,\,2,\dots,\,100\,\text{kg}$, who want to cross a river. They have a small boat which can lift at most $100\,\text{kg}$ each time without sinking. For each journey of the boat a non-empty subset of the dwarves to be taken to the other side is chosen and one of these dwarves is chosen as the $\emph{rower}$ for that journey. Since return journeys are counter-current, no dwarf is able to do the rower for more than one return journey. Is it possible for all the dwarves to reach the other side of the river?
1 reply
Experia
Apr 23, 2022
Radin_
2 hours ago
J
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Regarding Maaths olympiad prepration
omega2007   4
N 2 hours ago by omega2007
<Hey Everyone'>
I'm 10 grader student and Im starting prepration for maths olympiad..>>> From scratch (not 2+2=4 )

Do you haves compiled resources of Handouts,
PDF,
Links,
List of books topic wise
which are shared on AOPS (and from your perspective) for maths olympiad and any useful thing, which will help me in boosting Maths olympiad prepration.
4 replies
omega2007
Yesterday at 3:13 PM
omega2007
2 hours ago
J
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square root problem that involves geometry
kjhgyuio   2
N 3 hours ago by ND_
If x is a nonnegative real number , find the minimum value of √x^2+4 + √x^2 -24x +153

2 replies
kjhgyuio
4 hours ago
ND_
3 hours ago
J
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[$10K+ IN PRIZES] Poolesville Math Tournament (PVMT) 2025
qwerty123456asdfgzxcvb   4
N 4 hours ago by qwerty123456asdfgzxcvb
Hi everyone!

After the resounding success of the first three years of PVMT, the Poolesville High School Math Team is excited to announce the fourth annual Poolesville High School Math Tournament (PVMT)! The PVMT team includes a MOPper and multiple USA(J)MO and AIME qualifiers!

PVMT is open to all 6th-9th graders in the country (including rising 10th graders). Students will compete in teams of up to 4 people, and each participant will take three subject tests as well as the team round. The contest is completely free, and will be held virtually on June 7, 2025, from 10:00 AM to 4:00 PM (EST).

Additionally, thanks to our sponsors, we will be awarding approximately $10K+ worth of prizes (including gift cards, Citadel merch, AoPS coupons, Wolfram licenses) to top teams and individuals. More details regarding the actual prizes will be released as we get closer to the competition date.

Further, newly for this year we might run some interesting mini-events, which we will announce closer to the competition date, such as potentially a puzzle hunt and integration bee!

If you would like to register for the competition, the registration form can be found at https://pvmt.org/register.html.

Additionally, more information about PVMT can be found at https://pvmt.org

If you have any questions not answered in the below FAQ, feel free to ask in this thread or email us at falconsdomath@gmail.com!

We look forward to your participation!

FAQ
4 replies
qwerty123456asdfgzxcvb
Today at 12:23 AM
qwerty123456asdfgzxcvb
4 hours ago
J
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Assisted perpendicular chasing
sarjinius   5
N 5 hours ago by hukilau17
Source: Philippine Mathematical Olympiad 2025 P7
In acute triangle $ABC$ with circumcenter $O$ and orthocenter $H$, let $D$ be an arbitrary point on the circumcircle of triangle $ABC$ such that $D$ does not lie on line $OB$ and that line $OD$ is not parallel to line $BC$. Let $E$ be the point on the circumcircle of triangle $ABC$ such that $DE$ is perpendicular to $BC$, and let $F$ be the point on line $AC$ such that $FA = FE$. Let $P$ and $R$ be the points on the circumcircle of triangle $ABC$ such that $PE$ is a diameter, and $BH$ and $DR$ are parallel. Let $M$ be the midpoint of $DH$.
(a) Show that $AP$ and $BR$ are perpendicular.
(b) Show that $FM$ and $BM$ are perpendicular.
5 replies
sarjinius
Mar 9, 2025
hukilau17
5 hours ago
J
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AMC 10/AIME Study Forum
PatTheKing806   117
N 5 hours ago by PatTheKing806
[center]

Me (PatTheKing806) and EaZ_Shadow have created a AMC 10/AIME Study Forum! Hopefully, this forum wont die quickly. To signup, do /join or \join.

Click here to join! (or do some pushups) :P

People should join this forum if they are wanting to do well on the AMC 10 next year, trying get into AIME, or loves math!
117 replies
PatTheKing806
Mar 27, 2025
PatTheKing806
5 hours ago
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Tangent.
steven_zhang123   2
N 5 hours ago by AshAuktober
Source: China TST 2001 Quiz 6 P1
In \( \triangle ABC \) with \( AB > BC \), a tangent to the circumcircle of \( \triangle ABC \) at point \( B \) intersects the extension of \( AC \) at point \( D \). \( E \) is the midpoint of \( BD \), and \( AE \) intersects the circumcircle of \( \triangle ABC \) at \( F \). Prove that \( \angle CBF = \angle BDF \).
2 replies
steven_zhang123
Mar 23, 2025
AshAuktober
5 hours ago
J
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9 Which math contest is your favorite?
mdk2013   62
N Today at 1:52 AM by abbominable_sn0wman
links for details on each comp

i think thats all the major ones, comment if you have any more that i forgot to include

upvote if you're like me and you think MATHCOUNTS is obv better!

EDIT: i forgot ARML and JBMO, comment if you like those
62 replies
mdk2013
Mar 30, 2025
abbominable_sn0wman
Today at 1:52 AM
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USA(J)MO qualification
mathkidAP   13
N Today at 1:47 AM by PatTheKing806
Hello. I am an 8th grade student who wants to make jmo or usamo. How much practice do i need for this? i have a 63 on amc 10b and i mock roughly 90-100s on most amc 10s.
13 replies
mathkidAP
Yesterday at 2:03 AM
PatTheKing806
Today at 1:47 AM
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JMPSC Year 3 Problems/Results/Statistics
samrocksnature   3
N Aug 20, 2023 by samrocksnature
Hey everyone!

Thank you to all who participated in the third year of JMPSC. The solutions, statistics, and problems are linked to this post, and the top 20 of each division can be found here.

Enjoy the problems!

3 replies
samrocksnature
Aug 19, 2023
samrocksnature
Aug 20, 2023
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JMPSC Year 3 Problems/Results/Statistics
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Reveal topic tags
JMPSC
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samrocksnature
8791 posts
samrocksnature
#1 h  Aug 19, 2023, 10:42 PM • 6 Y
Y by aidan0626, kante314, Math4Life7, KevinYang2.71, SouradipClash_03, Danielzh
Hey everyone!

Thank you to all who participated in the third year of JMPSC. The solutions, statistics, and problems are linked to this post, and the top 20 of each division can be found here.

Enjoy the problems!
Attachments:
JMPSC3Stats.pdf (91kb)
JMPSC3Solutions.pdf (523kb)
JMPSC3Problems.pdf (445kb)
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Math4Life7
1703 posts
Math4Life7
#3 h  Aug 20, 2023, 12:54 AM
Y by
I am pretty sure that the solution to problem 12 d1r2 has a typo
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palindrome868
1174 posts
palindrome868
#4 h  Aug 20, 2023, 12:55 AM
Y by
imma check the sol for that problem soon
this message will be edited when i do so

uh, i don't see a typo, the solution seems good to me?
This post has been edited 1 time. Last edited by palindrome868, Aug 20, 2023, 2:09 AM
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samrocksnature
8791 posts
samrocksnature
#5 h  Aug 20, 2023, 1:04 AM • 2 Y
Y by aie8920, MathFan335
Math4Life7 wrote:
I am pretty sure that the solution to problem 12 d1r2 has a typo

Thank you Jacob for writing all the solutions!
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