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k a May Highlights and 2025 AoPS Online Class Information
jlacosta   0
May 1, 2025
May is an exciting month! National MATHCOUNTS is the second week of May in Washington D.C. and our Founder, Richard Rusczyk will be presenting a seminar, Preparing Strong Math Students for College and Careers, on May 11th.

Are you interested in working towards MATHCOUNTS and don’t know where to start? We have you covered! If you have taken Prealgebra, then you are ready for MATHCOUNTS/AMC 8 Basics. Already aiming for State or National MATHCOUNTS and harder AMC 8 problems? Then our MATHCOUNTS/AMC 8 Advanced course is for you.

Summer camps are starting next month at the Virtual Campus in math and language arts that are 2 - to 4 - weeks in duration. Spaces are still available - don’t miss your chance to have an enriching summer experience. 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 upcoming events:
[list][*]May 9th, 4:30pm PT/7:30pm ET, Casework 2: Overwhelming Evidence — A Text Adventure, a game where participants will work together to navigate the map, solve puzzles, and win! All are welcome.
[*]May 19th, 4:30pm PT/7:30pm ET, What's Next After Beast Academy?, designed for students finishing Beast Academy and ready for Prealgebra 1.
[*]May 20th, 4:00pm PT/7:00pm ET, Mathcamp 2025 Qualifying Quiz Part 1 Math Jam, Problems 1 to 4, join the Canada/USA Mathcamp staff for this exciting Math Jam, where they discuss solutions to Problems 1 to 4 of the 2025 Mathcamp Qualifying Quiz!
[*]May 21st, 4:00pm PT/7:00pm ET, Mathcamp 2025 Qualifying Quiz Part 2 Math Jam, Problems 5 and 6, Canada/USA Mathcamp staff will discuss solutions to Problems 5 and 6 of the 2025 Mathcamp Qualifying Quiz![/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
May 1, 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
J
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Zack likes Moving Points
pinetree1   73
N an hour ago by NumberzAndStuff
Source: USA TSTST 2019 Problem 5
Let $ABC$ be an acute triangle with orthocenter $H$ and circumcircle $\Gamma$. A line through $H$ intersects segments $AB$ and $AC$ at $E$ and $F$, respectively. Let $K$ be the circumcenter of $\triangle AEF$, and suppose line $AK$ intersects $\Gamma$ again at a point $D$. Prove that line $HK$ and the line through $D$ perpendicular to $\overline{BC}$ meet on $\Gamma$.

Gunmay Handa
73 replies
pinetree1
Jun 25, 2019
NumberzAndStuff
an hour ago
J
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Domain and Inequality
Kunihiko_Chikaya   1
N an hour ago by Mathzeus1024
Source: 2018 The University of Tokyo entrance exam / Humanities, Problem 1
Define on a coordinate plane, the parabola $C:y=x^2-3x+4$ and the domain $D:y\geq x^2-3x+4.$
Suppose that two lines $l,\ m$ passing through the origin touch $C$.

(1) Let $A$ be a mobile point on the parabola $C$. Let denote $L,\ M$ the distances between the point $A$ and the lines $l,\ m$ respectively. Find the coordinate of the point $A$ giving the minimum value of $\sqrt{L}+\sqrt{M}.$

(2) Draw the domain of the set of the points $P(p,\ q)$ on a coordinate plane such that for all points $(x,\ y)$ over the domain $D$, the inequality $px+qy\leq 0$ holds.
1 reply
Kunihiko_Chikaya
Feb 25, 2018
Mathzeus1024
an hour ago
J
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JBMO TST Bosnia and Herzegovina 2020 P1
Steve12345   3
N an hour ago by AylyGayypow009
Determine all four-digit numbers $\overline{abcd}$ which are perfect squares and for which the equality holds:
$\overline{ab}=3 \cdot \overline{cd} + 1$.
3 replies
Steve12345
Aug 10, 2020
AylyGayypow009
an hour ago
J
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Problem3
samithayohan   116
N an hour ago by fearsum_fyz
Source: IMO 2015 problem 3
Let $ABC$ be an acute triangle with $AB > AC$. Let $\Gamma $ be its circumcircle, $H$ its orthocenter, and $F$ the foot of the altitude from $A$. Let $M$ be the midpoint of $BC$. Let $Q$ be the point on $\Gamma$ such that $\angle HQA = 90^{\circ}$ and let $K$ be the point on $\Gamma$ such that $\angle HKQ = 90^{\circ}$. Assume that the points $A$, $B$, $C$, $K$ and $Q$ are all different and lie on $\Gamma$ in this order.

Prove that the circumcircles of triangles $KQH$ and $FKM$ are tangent to each other.

Proposed by Ukraine
116 replies
samithayohan
Jul 10, 2015
fearsum_fyz
an hour ago
J
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geometry problem
invt   0
an hour ago
In a triangle $ABC$ with $\angle B<\angle C$, denote its incenter and midpoint of $BC$ by $I$, $M$, respectively. Let $C'$ be the reflected point of $C$ wrt $AI$. Let the lines $MC'$ and $CI$ meet at $X$. Suppose that $\angle XAI=\angle XBI=90^{\circ}$. Prove that $\angle C=2\angle B$.
0 replies
invt
an hour ago
0 replies
J
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the locus of $P$
littletush   10
N 2 hours ago by SuperBarsh
Source: Italy TST 2009 p2
$ABC$ is a triangle in the plane. Find the locus of point $P$ for which $PA,PB,PC$ form a triangle whose area is equal to one third of the area of triangle $ABC$.
10 replies
littletush
Mar 10, 2012
SuperBarsh
2 hours ago
J
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Abelkonkurransen 2025 3b
Lil_flip38   3
N 2 hours ago by Adywastaken
Source: abelkonkurransen
An acute angled triangle \(ABC\) has circumcenter \(O\). The lines \(AO\) and \(BC\) intersect at \(D\), while \(BO\) and \(AC\) intersect at \(E\) and \(CO\) and \(AB\) intersect at \(F\). Show that if the triangles \(ABC\) and \(DEF\) are similar(with vertices in that order), than \(ABC\) is equilateral.
3 replies
Lil_flip38
Mar 20, 2025
Adywastaken
2 hours ago
J
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I got stuck in this combinatorics
artjustinhere237   3
N 2 hours ago by GreekIdiot
Let $S = \{1, 2, 3, \ldots, k\}$, where $k \geq 4$ is a positive integer.
Prove that there exists a subset of $S$ with exactly $k - 2$ elements such that the sum of its elements is a prime number.
3 replies
artjustinhere237
May 13, 2025
GreekIdiot
2 hours ago
J
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Geo metry
TUAN2k8   5
N 2 hours ago by Melid
Help me plss!
Given an acute triangle $ABC$. Points $D$ and $E$ lie on segments $AB$ and $AC$, respectively. Lines $BD$ and $CE$ intersect at point $F$. The circumcircles of triangles $BDF$ and $CEF$ intersect at a second point $P$. The circumcircles of triangles $ABC$ and $ADE$ intersect at a second point $Q$. Point $K$ lies on segment $AP$ such that $KQ \perp AQ$. Prove that triangles $\triangle BKD$ and $\triangle CKE$ are similar.
5 replies
TUAN2k8
May 6, 2025
Melid
2 hours ago
J
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power of a point
BekzodMarupov   2
N 2 hours ago by BekzodMarupov
Source: lemmas in olympiad geometry
Epsilon 1.3. 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.
2 replies
BekzodMarupov
Yesterday at 5:41 AM
BekzodMarupov
2 hours ago
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Introducing myself at AoPS, and what's your magic wand?
asuth_asuth   1175
N Today at 3:17 AM by LostInBali
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.
1175 replies
asuth_asuth
Mar 30, 2025
LostInBali
Today at 3:17 AM
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All Topics Marked
alpha31415   1
N Yesterday at 6:10 PM by jmr2010
Excuse me!
for I am a frashman in aops.I wonder how I could get back to mark all my read.All topics in the forum became as if they had been marked.Would someone please help me deal with it???
1 reply
alpha31415
Yesterday at 12:39 PM
jmr2010
Yesterday at 6:10 PM
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k profile pictures
happymoose666   1
N Thursday at 11:24 PM by RollingPanda4616
I'm pretty sure this question was raised before but why are their two different avatars?
1 reply
happymoose666
Thursday at 11:10 PM
RollingPanda4616
Thursday at 11:24 PM
J
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k Glitch or Bug?
awesometriangles   5
N May 14, 2025 by Craftybutterfly
I was asking for some $\LaTeX$ help in one of my classrooms, and one of the Halpers posted. Is this a glitch or a bug(see screenshot)?


It seems as though I can edit their post...
5 replies
awesometriangles
May 14, 2025
Craftybutterfly
May 14, 2025
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k FTW Composite Scoring
AIMETestTaker   8
N Apr 8, 2025 by aok
Hi, does anyone know what the formula for the composite FTW scoring is?

8 replies
AIMETestTaker
Apr 4, 2025
aok
Apr 8, 2025
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FTW Composite Scoring
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Reveal topic tags
FTW
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AIMETestTaker
2 posts
AIMETestTaker
#1 h  Apr 4, 2025, 4:07 PM • 1 Y
Y by PikaPika999
Hi, does anyone know what the formula for the composite FTW scoring is?
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Craftybutterfly
519 posts
Craftybutterfly
#2 h  Apr 4, 2025, 5:23 PM • 1 Y
Y by PikaPika999
I never played FTW but you can find out with simple math.
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Yrock
1294 posts
Yrock
#3 h  Apr 4, 2025, 5:24 PM • 1 Y
Y by PikaPika999
AIMETestTaker wrote:
Hi, does anyone know what the formula for the composite FTW scoring is?

dunno, all I know is that I hate it :|
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k1glaucus
687 posts
k1glaucus
#4 h  Apr 4, 2025, 5:32 PM • 1 Y
Y by PikaPika999
AIMETestTaker wrote:
Hi, does anyone know what the formula for the composite FTW scoring is?

the responses part seems to affect it a lot, time doesn't seem that important, and I can't really tell with the standard.
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aok
348 posts
aok
#5 h  Apr 7, 2025, 11:35 PM • 1 Y
Y by PikaPika999
the number of points is equal to all who get it riight. some number / people who get it right = points given
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Yrock
1294 posts
Yrock
#6 h  Apr 8, 2025, 2:59 AM • 1 Y
Y by PikaPika999
aok wrote:
the number of points is equal to all who get it riight. some number / people who get it right = points given

but there's also the time element in it.
Z Y
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derekwang2048
1227 posts
derekwang2048
#7 h  Apr 8, 2025, 3:23 AM • 1 Y
Y by PikaPika999
I'm pretty sure time doesn't matter for composite
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k1glaucus
687 posts
k1glaucus
#8 h  Apr 8, 2025, 12:27 PM • 1 Y
Y by PikaPika999
@bove quoting the information page for FTW:
FTW wrote:
Composite: Points are awarded based on a combination of time, ranking, and response methods."
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aok
348 posts
aok
#9 h  Apr 8, 2025, 10:33 PM • 1 Y
Y by PikaPika999
well when I did composite, it didn't matter
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