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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 Suggestion Form
jwelsh   0
May 6, 2021
Hello!

Given the number of suggestions we’ve been receiving, we’re transitioning to a suggestion form. If you have a suggestion for the AoPS website, please submit the Google Form:
Suggestion Form

To keep all new suggestions together, any new suggestion threads posted will be deleted.

Please remember that if you find a bug outside of FTW! (after refreshing to make sure it’s not a glitch), make sure you’re following the How to write a bug report instructions and using the proper format to report the bug.

Please check the FTW! thread for bugs and post any new ones in the For the Win! and Other Games Support Forum.
0 replies
jwelsh
May 6, 2021
0 replies
J
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k i Read me first / How to write a bug report
slester   3
N May 4, 2019 by LauraZed
Greetings, AoPS users!

If you're reading this post, that means you've come across some kind of bug, error, or misbehavior, which nobody likes! To help us developers solve the problem as quickly as possible, we need enough information to understand what happened. Following these guidelines will help us squash those bugs more effectively.

Before submitting a bug report, please confirm the issue exists in other browsers or other computers if you have access to them.

For a list of many common questions and issues, please see our user created FAQ, Community FAQ, or For the Win! FAQ.

What is a bug?
A bug is a misbehavior that is reproducible. If a refresh makes it go away 100% of the time, then it isn't a bug, but rather a glitch. That's when your browser has some strange file cached, or for some reason doesn't render the page like it should. Please don't report glitches, since we generally cannot fix them. A glitch that happens more than a few times, though, could be an intermittent bug.

If something is wrong in the wiki, you can change it! The AoPS Wiki is user-editable, and it may be defaced from time to time. You can revert these changes yourself, but if you notice a particular user defacing the wiki, please let an admin know.

The subject
The subject line should explain as clearly as possible what went wrong.

Bad: Forum doesn't work
Good: Switching between threads quickly shows blank page.

The report
Use this format to report bugs. Be as specific as possible. If you don't know the answer exactly, give us as much information as you know. Attaching a screenshot is helpful if you can take one.

Summary of the problem:
Page URL:
Steps to reproduce:
1.
2.
3.
...
Expected behavior:
Frequency:
Operating system(s):
Browser(s), including version:
Additional information:

If your computer or tablet is school issued, please indicate this under Additional information.

Example
Summary of the problem: When I click back and forth between two threads in the site support section, the content of the threads no longer show up. (See attached screenshot.)
Page URL: http://artofproblemsolving.com/community/c10_site_support
Steps to reproduce:
1. Go to the Site Support forum.
2. Click on any thread.
3. Click quickly on a different thread.
Expected behavior: To see the second thread.
Frequency: Every time
Operating system: Mac OS X
Browser: Chrome and Firefox
Additional information: Only happens in the Site Support forum. My tablet is school issued, but I have the problem at both school and home.

How to take a screenshot
Mac OS X: If you type ⌘+Shift+4, you'll get a "crosshairs" that lets you take a custom screenshot size. Just click and drag to select the area you want to take a picture of. If you type ⌘+Shift+4+space, you can take a screenshot of a specific window. All screenshots will show up on your desktop.

Windows: Hit the Windows logo key+PrtScn, and a screenshot of your entire screen. Alternatively, you can hit Alt+PrtScn to take a screenshot of the currently selected window. All screenshots are saved to the Pictures → Screenshots folder.

Advanced
If you're a bit more comfortable with how browsers work, you can also show us what happens in the JavaScript console.

In Chrome, type CTRL+Shift+J (Windows, Linux) or ⌘+Option+J (Mac).
In Firefox, type CTRL+Shift+K (Windows, Linux) or ⌘+Option+K (Mac).
In Internet Explorer, it's the F12 key.
In Safari, first enable the Develop menu: Preferences → Advanced, click "Show Develop menu in menu bar." Then either go to Develop → Show Error console or type Option+⌘+C.

It'll look something like this:
IMAGE
3 replies
slester
Apr 9, 2015
LauraZed
May 4, 2019
J
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k i Community Safety
dcouchman   0
Jan 18, 2018
If you find content on the AoPS Community that makes you concerned for a user's health or safety, please alert AoPS Administrators using the report button (Z) or by emailing sheriff@aops.com . You should provide a description of the content and a link in your message. If it's an emergency, call 911 or whatever the local emergency services are in your country.

Please also use those steps to alert us if bullying behavior is being directed at you or another user. Content that is "unlawful, harmful, threatening, abusive, harassing, tortuous, defamatory, vulgar, obscene, libelous, invasive of another's privacy, hateful, or racially, ethnically or otherwise objectionable" (AoPS Terms of Service 5.d) or that otherwise bullies people is not tolerated on AoPS, and accounts that post such content may be terminated or suspended.
0 replies
dcouchman
Jan 18, 2018
0 replies
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old problem from an open contest
Darealzolt   1
N 3 hours ago by alexheinis
Given that $a, b \in \mathbb{R}$ satisfy
\[ a + \frac{1}{a + 2015} = b - 4030 + \frac{1}{b - 2015} \]and $|a - b| > 5000$. Determine the value of
\[ \frac{ab}{2015} - a + b. \]
1 reply
Darealzolt
Yesterday at 1:41 AM
alexheinis
3 hours ago
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A Collection of Good Problems from my end
SomeonecoolLovesMaths   12
N 3 hours ago by SomeonecoolLovesMaths
This is a collection of good problems and my respective attempts to solve them. I would like to encourage everyone to post their solutions to these problems, if any. This will not only help others verify theirs but also perhaps bring forward a different approach to the problem. I will constantly try to update the pool of questions.

The difficulty level of these questions vary from AMC 10 to AIME. (Although the main pool of questions were prepared as a mock test for IOQM over the years)

Problem 1

Problem 2

Problem 3

Problem 4

Problem 5
12 replies
SomeonecoolLovesMaths
May 4, 2025
SomeonecoolLovesMaths
3 hours ago
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Geometry Proof
strongstephen   2
N 4 hours ago by greenturtle3141
Proof that choosing four distinct points at random has an equal probability of getting a convex quadrilateral vs a concave one.
not cohesive proof alert!

NOTE: By choosing four distinct points, that means no three points lie on the same line on the Gaussian Plane.

Start by picking three of the four points. Next, graph the regions where the fourth point would make the quadrilateral convex or concave. In diagram 1 below, you can see the regions where the fourth point would be convex or concave. Of course, there is the centre region (the shaded triangle), but in an infinite plane, the probability the fourth point ends up in the finite region approaches 0.

Next, I want to prove to you the area of convex/concave, or rather, the probability a point ends up in each area, is the same. Referring to the second diagram, you can flip each concave region over the line perpendicular to the angle bisector of which the region is defined. (Just look at it and you'll get what it means.) Now, each concave region has an almost perfect 1:1 probability correspondence to another convex region. The only difference is the finite region (the triangle, shaded). Again, however, the actual significance (probability) of this approaches 0.

If I call each of the convex region's probability P(a), P(c), and P(e) and the concave ones P(b), P(d), P(f), assuming areas a and b are on opposite sides (same with c and d, e and f) you can get:
P(a) = P(b)
P(c) = P(d)
P(e) = P(f)

and P(a) + P(c) + P(e) = P(convex)
and P(b) + P(d) + P(f) = P(concave)

therefore:
P(convex) = P(concave)
2 replies
strongstephen
Today at 4:54 AM
greenturtle3141
4 hours ago
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BABBAGE'S THEOREM EXTENSION
Mathgloggers   4
N 4 hours ago by Mathgloggers
A few days ago I came across. this interesting result is someone interested in proving this.

$\boxed{\sum_{k=1}^{p-1} \frac{1}{k} \equiv \sum_{k=p+1}^{2p-1} \frac{1}{k} \equiv \sum_{k=2p+1}^{3p-1}\frac{1}{k} \equiv.....\sum_{k=p(p-1)+1}^{p^2-1}\frac{1}{k} \equiv 0(mod p^2)}$
4 replies
Mathgloggers
Apr 29, 2025
Mathgloggers
4 hours ago
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Error in forum
Speedysolver1   3
N Yesterday at 4:27 AM by Craftybutterfly
Will put video
3 replies
Speedysolver1
Apr 23, 2025
Craftybutterfly
Yesterday at 4:27 AM
J
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k May the 4th (Late lol)
AbhayAttarde01   4
N Yesterday at 12:26 AM by PikaPika999
nobody said this yet in site support????
Happy May 4th!
may the 4th be with you
and me my ap exams are tomorrow please be real
4 replies
AbhayAttarde01
Sunday at 11:38 PM
PikaPika999
Yesterday at 12:26 AM
J
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k question
JohannIsBach   2
N Sunday at 10:42 PM by bpan2021
i have a question. where can u find what are hte most active forums?
2 replies
JohannIsBach
Sunday at 10:33 PM
bpan2021
Sunday at 10:42 PM
J
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k *RESOLVED* This has been going on for a while now, can anyone else relate?
jmr2010   3
N May 3, 2025 by jmr2010
Most of the time when I type in something for the tags or search for a user, the AoPS suggestion box pops up, and most of the time, when I click the suggestion, the box just disappears, meaning the automatic system usually never works
3 replies
jmr2010
Apr 29, 2025
jmr2010
May 3, 2025
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Cannot post PHP
char0221   4
N May 2, 2025 by k1glaucus
Summary of the problem: If I try to post anything with PHP (a coding language), it
Page URL: In any forum or private messages
Steps to reproduce:
1. Create a post.
2. Put some PHP inside, can't give example
Expected behavior: Should post the message
Frequency: 100%
Operating system(s): macOS Sequoia 15.2.1
Browser(s), including version: Safari
Additional information: See attachments
4 replies
char0221
Apr 30, 2025
k1glaucus
May 2, 2025
J
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k Side Panel UI Glitch
MathPerson12321   3
N May 1, 2025 by Demetri
Ill add more detail soon but on the side panel with the global feed, my feeds, private messages, and bookmarked threads/forums, the 2nd and 4th one I just mentioned are glitched. The 2nd one has the settings icon and then a music icon, and the 4th has an aops mini cube, the share button, and another that I don't know what it is.
Private messages are also being weird as the right panel with the edit button for example is offset.
3 replies
MathPerson12321
May 1, 2025
Demetri
May 1, 2025
J
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k How to delete a private forum you created
Platinum_Dragon   2
N Apr 30, 2025 by jlacosta
Is this possible? thank you
2 replies
Platinum_Dragon
Apr 30, 2025
jlacosta
Apr 30, 2025
J
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k How to remove tags from a PM after you've removed yourself from it
Platinum_Dragon   2
N Apr 29, 2025 by Platinum_Dragon
Is it possible? Because it's kind of annoying to have a whole bunch of tags that stick around forever.

thank you
2 replies
Platinum_Dragon
Apr 29, 2025
Platinum_Dragon
Apr 29, 2025
J
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k Reaper....
Happycat2   22
N Apr 29, 2025 by jlacosta
Can someone explain what the reaper is this time? I'm sorry but I don't know what "Rapper ear error a pear perrier ear ape ea games" means.
22 replies
Happycat2
Apr 27, 2025
jlacosta
Apr 29, 2025
J
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k Reaper Description
Jwenslawski   1
N Apr 29, 2025 by LostInBali
What does the Reaper game description mean?

"rapper eaE error a Sear perriTr ear apeIea games"

Is it in another language?
1 reply
Jwenslawski
Apr 29, 2025
LostInBali
Apr 29, 2025
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Fun & Simple puzzle
Kscv   7
N Apr 25, 2025 by vanstraelen
$\angle DCA=45^{\circ},$ $\angle BDC=15^{\circ},$ $\overline{AC}=\overline{CB}$

$\angle ADC=?$
7 replies
Kscv
Apr 13, 2025
vanstraelen
Apr 25, 2025
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Fun & Simple puzzle
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Reveal topic tags
geometry
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Kscv
182 posts
Kscv
#1 h  Apr 13, 2025, 1:46 AM
Y by
$\angle DCA=45^{\circ},$ $\angle BDC=15^{\circ},$ $\overline{AC}=\overline{CB}$

$\angle ADC=?$
Attachments:
This post has been edited 1 time. Last edited by Kscv, Apr 13, 2025, 1:49 AM
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Kscv
182 posts
Kscv
#2 h  Apr 13, 2025, 1:50 AM
Y by
made a typo mb

also bonus points if you do it without LoS and LoC :3
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Kempu33334
609 posts
Kempu33334
#3 h  Apr 13, 2025, 2:07 AM
Y by
Kscv wrote:
$\angle DCA=45^{\circ},$ $\angle BDC=15^{\circ},$ $\overline{AC}=\overline{CB}$

$\angle ADC=?$

Are we to ignore $A'$?
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vanstraelen
9010 posts
vanstraelen
#4 h  Apr 13, 2025, 9:01 AM
Y by
Given $\triangle ABD\ :\ A(0,0),B(2b,0),D$ and $C(b,0)$.

The line $BD\ :\ y=-\frac{\sqrt{3}}{3}(x-2b)$ intersects the line $CD\ :\ y=-x+b$
in the point $D(\frac{b(\sqrt{3}-1)}{2},\frac{b(3-\sqrt{3})}{2}\ )$.
Slope of the line $AD\ :\ m_{AD}=\sqrt{3}$, then $\angle CAD=60^{\circ}$ and $\angle CDA=75^{\circ}$.
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Kscv
182 posts
Kscv
#5 h  Apr 25, 2025, 12:32 AM
Y by
Kempu33334 wrote:

Are we to ignore $A'$?

Yes, geogebra issue.
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Kscv
182 posts
Kscv
#6 h  Apr 25, 2025, 12:37 AM
Y by
vanstraelen wrote:
Given $\triangle ABD\ :\ A(0,0),B(2b,0),D$ and $C(b,0)$.

The line $BD\ :\ y=-\frac{\sqrt{3}}{3}(x-2b)$ intersects the line $CD\ :\ y=-x+b$
in the point $D(\frac{b(\sqrt{3}-1)}{2},\frac{b(3-\sqrt{3})}{2}\ )$.
Slope of the line $AD\ :\ m_{AD}=\sqrt{3}$, then $\angle CAD=60^{\circ}$ and $\angle CDA=75^{\circ}$.

Try again, also that angle doesnt really seem like a 75 to me... ;w;
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AbbyWong
171 posts
AbbyWong
#7 h  Apr 25, 2025, 4:58 AM
Y by
it is 30 degrees
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vanstraelen
9010 posts
vanstraelen
#8 h  Apr 25, 2025, 7:46 AM
Y by
Correction.

Given $\triangle ABD\ :\ A(0,0),B(2b,0),D$ and $C(b,0)$.
The line $BD\ :\ y=-\frac{\sqrt{3}}{3}(x-2b)$ intersects the line $CD\ :\ y=-x+b$
in the point $D(\frac{b(1-\sqrt{3})}{2},\frac{b(1+\sqrt{3})}{2}\ )$.
Slope of the line $AD\ :\ m_{AD}=\frac{1+\sqrt{3}}{1-\sqrt{3}}$, then $\angle CAD=105^{\circ}$ and $\angle CDA=30^{\circ}$.
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