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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
[*]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.

Introductory: Grades 5-10

Prealgebra 1 Self-Paced

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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
J
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Or statement function
ItzsleepyXD   0
13 minutes ago
Source: Own , Mock Thailand Mathematic Olympiad P2
Find all $f: \mathbb{R} \to \mathbb{Z^+}$ such that $$f(x+f(y))=f(x)+f(y)+1\quad\text{ or }\quad f(x)+f(y)-1$$for all real number $x$ and $y$
0 replies
ItzsleepyXD
13 minutes ago
0 replies
J
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Trivial fun Equilateral
ItzsleepyXD   0
15 minutes ago
Source: Own , Mock Thailand Mathematic Olympiad P1
Let $ABC$ be a scalene triangle with point $P$ and $Q$ on the plane such that $\triangle BPC , \triangle CQB$ is an equilateral . Let $AB$ intersect $CP$ and $CQ$ at $X$ and $Z$ respectively and $AC$ intersect $BP$ and $BQ$ at $Y$ and $W$ respectively .
Prove that $XY\parallel ZW$
0 replies
ItzsleepyXD
15 minutes ago
0 replies
J
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Inspired by old results
sqing   4
N 38 minutes ago by sqing
Source: Own
Let $ a,b>0 , a^2+b^2+ab+a+b=5 . $ Prove that
$$ \frac{ 1 }{a+b+ab+1}+\frac{6}{a^2+b^2+ab+1}\geq \frac{7}{4}$$$$ \frac{ 1 }{a+b+ab+1}+\frac{1}{a^2+b^2+ab+1}\geq \frac{1}{2}$$$$ \frac{41}{a+b+2}+\frac{ab}{a^3+b^3+2} \geq \frac{21}{2}$$
4 replies
sqing
Yesterday at 12:29 PM
sqing
38 minutes ago
J
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D1024 : Can you do that?
Dattier   1
N 42 minutes ago by Dattier
Source: les dattes à Dattier
Let $x_{n+1}=x_n^2+1$ and $x_0=1$.

Can you calculate $\sum\limits_{i=1}^{2^{2025}} x_i \mod 10^{30}$?
1 reply
Dattier
Yesterday at 5:11 PM
Dattier
42 minutes ago
J
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F(n,r)=(n+1)/(r+1)
orl   23
N an hour ago by Nguyen
Source: IMO 1981, Day 1, Problem 2
Take $r$ such that $1\le r\le n$, and consider all subsets of $r$ elements of the set $\{1,2,\ldots,n\}$. Each subset has a smallest element. Let $F(n,r)$ be the arithmetic mean of these smallest elements. Prove that: \[ F(n,r)={n+1\over r+1}. \]
23 replies
orl
Nov 11, 2005
Nguyen
an hour ago
J
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inequality (another entrance exam)
nai0610   3
N an hour ago by lbh_qys
Given positive real numbers $a,b,c$ satisfying
$(a+2)b^2+(b+2)c^2+(c+2)a^2\geq 8+abc$
prove that $2(ab+bc+ca)\leq a^2(a+b)+b^2(b+c)+c^2(c+a)$
3 replies
nai0610
Jun 2, 2024
lbh_qys
an hour ago
J
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hard inequalities
pennypc123456789   2
N an hour ago by pennypc123456789
Given $x,y,z$ be the positive real number. Prove that

$\frac{2xy}{\sqrt{2xy(x^2+y^2)}} + \frac{2yz}{\sqrt{2yz(y^2+z^2)}} + \frac{2xz}{\sqrt{2xz(x^2+z^2)}} \le \frac{2(x^2+y^2+z^2) + xy+yz+xz}{x^2+y^2+z^2}$
2 replies
pennypc123456789
Today at 12:12 AM
pennypc123456789
an hour ago
J
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Easy Geometry
ayan.nmath   41
N 2 hours ago by L13832
Source: Indian TST 2019 Practice Test 2 P1
Let the points $O$ and $H$ be the circumcenter and orthocenter of an acute angled triangle $ABC.$ Let $D$ be the midpoint of $BC.$ Let $E$ be the point on the angle bisector of $\angle BAC$ such that $AE\perp HE.$ Let $F$ be the point such that $AEHF$ is a rectangle. Prove that $D,E,F$ are collinear.
41 replies
ayan.nmath
Jul 17, 2019
L13832
2 hours ago
J
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Construct
Pomegranat   1
N 2 hours ago by quacksaysduck
Source: idk
Let \( p \) be a prime number. Prove that there exists a natural number \( n \) such that
\[ p \mid 2024^n - n. \]
1 reply
Pomegranat
2 hours ago
quacksaysduck
2 hours ago
J
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Introducing myself at AoPS, and what's your magic wand?
asuth_asuth   1047
N 2 hours ago by RadioDemon666
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.
1047 replies
asuth_asuth
Mar 30, 2025
RadioDemon666
2 hours ago
J
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inequality problem
pennypc123456789   3
N 2 hours ago by GeoMorocco
Given $a,b,c$ be positive real numbers . Prove that
$$\frac{ab}{(a+b)^2} +\frac{bc}{(b+c)^2}+\frac{ac}{(a+c)^2} \ge \frac{6abc }{(a+b)(b+c)(a+c)}$$
3 replies
pennypc123456789
Yesterday at 2:42 PM
GeoMorocco
2 hours ago
J
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This has been going on for a while now, can anyone else relate?
jmr2010   2
N Today at 3:02 AM by valisaxieamc
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
2 replies
jmr2010
Yesterday at 7:16 PM
valisaxieamc
Today at 3:02 AM
J
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Cannot post PHP
char0221   2
N Today at 2:01 AM by bpan2021
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
2 replies
char0221
Today at 1:23 AM
bpan2021
Today at 2:01 AM
J
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k How to remove tags from a PM after you've removed yourself from it
Platinum_Dragon   2
N Yesterday at 7:32 PM 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
Yesterday at 7:25 PM
Platinum_Dragon
Yesterday at 7:32 PM
J
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J
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k Typo in blog info
Craftybutterfly   3
N Apr 16, 2025 by bpan2021
I found a typo in blog css. It is supposed to say Edit your blog's CSS in the text area below. not Edit your blog's CSS in the textarea below.
3 replies
Craftybutterfly
Apr 16, 2025
bpan2021
Apr 16, 2025
J
Typo in blog info
G H J
Reveal topic tags
blogs
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G H BBookmark kLocked kLocked NReply
The post below has been deleted. Click to close.
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Craftybutterfly
410 posts
Craftybutterfly
#1 h  Apr 16, 2025, 6:26 AM
Y by
I found a typo in blog css. It is supposed to say Edit your blog's CSS in the text area below. not Edit your blog's CSS in the textarea below.
Attachments:
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The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
aidan0626
1876 posts
aidan0626
#2 h  Apr 16, 2025, 6:31 AM
Y by
this is not a typo :)
textarea is an html element that allows input with multiple lines... oh wait
inspect element also shows it's a textarea as well
Z Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Craftybutterfly
410 posts
Craftybutterfly
#3 h  Apr 16, 2025, 6:35 AM
Y by
Shouldn't it be text area?
Z Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
bpan2021
2625 posts
bpan2021
#4 h  Apr 16, 2025, 11:15 AM
Y by
If "textarea" matches the name of an HTML element that it's referring to, then it's likely intentional.
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