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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
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
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
mc nats predictions
ethan2011   7
N 6 minutes ago by awarrier
My team predictions:
1. CA
2. NY
3. NJ
4. TX
5. MA
6. WA
7. NC
8. IL
9. IN
10. AR
List any predicted cdr quals, with reason why they would. Also, give opinions on team ranking predictions.
7 replies
ethan2011
an hour ago
awarrier
6 minutes ago
NT functional equation on positive integers
RootofUnityfilter   0
12 minutes ago
Source: my teacher
Let $\mathbb{Z^+}$ denote the set of positive integers.
Find all function $f: \mathbb{Z^+} \rightarrow \mathbb{Z^+}$ such that for all $m, n \in \mathbb{Z^+}$,
\[f(mn)^2 = f(m^2)f(f(n))f(mf(n))\]if and only if $\gcd(m, n) = 1$
0 replies
RootofUnityfilter
12 minutes ago
0 replies
Inspired by old results
sqing   0
21 minutes ago
Source: Own
Let $ a,b,c \ge  \frac{1}{21} $ and $ a+b+c=1. $. Prove that
$$(a^2-ab+b^2)(b^2-bc+c^2)(c^2-ca+a^2)\geq\frac{1}{729} $$Let $ a,b,c \ge  \frac{1}{10} $ and $ a+b+c=2. $. Prove that
$$(a^2-ab+b^2)(b^2-bc+c^2)(c^2-ca+a^2)\geq\frac{64}{729} $$Let $ a,b,c \ge  \frac{1}{11} $ and $ a+b+c=2. $. Prove that
$$(a^2-ab+b^2)(b^2-bc+c^2)(c^2-ca+a^2)\geq \frac{145161}{1771561} $$
0 replies
1 viewing
sqing
21 minutes ago
0 replies
There is a tri-blued unit square
Ankoganit   18
N 34 minutes ago by alexanderhamilton124
Source: India TST 2016 Day 3 Problem 3
Let $n$ be an odd natural number. We consider an $n\times n$ grid which is made up of $n^2$ unit squares and $2n(n+1)$ edges. We colour each of these edges either $\color{red} \textit{red}$ or $\color{blue}\textit{blue}$. If there are at most $n^2$ $\color{red} \textit{red}$ edges, then show that there exists a unit square at least three of whose edges are $\color{blue}\textit{blue}$.
18 replies
Ankoganit
Jul 22, 2016
alexanderhamilton124
34 minutes ago
D is incenter
Layaliya   2
N 36 minutes ago by Lil_flip38
Source: From my friend in Indonesia
Given an acute triangle \( ABC \) where \( AB > AC \). Point \( O \) is the circumcenter of triangle \( ABC \), and \( P \) is the projection of point \( A \) onto line \( BC \). The midpoints of \( BC \), \( CA \), and \( AB \) are \( D \), \( E \), and \( F \), respectively. The line \( AO \) intersects \( DE \) and \( DF \) at points \( Q \) and \( R \), respectively. Prove that \( D \) is the incenter of triangle \( PQR \).
2 replies
Layaliya
3 hours ago
Lil_flip38
36 minutes ago
max number of candies
orangefronted   3
N 40 minutes ago by fruitmonster97
A store sells a strawberry flavoured candy for 1 dollar each. The store offers a promo where every 4 candy wrappers can be exchanged for one candy. If there is no limit to how many times you can exchange candy wrappers for candies, what is the maximum number of candies I can obtain with 100 dollars?
3 replies
orangefronted
Today at 6:43 AM
fruitmonster97
40 minutes ago
Mmo 9-10 graders P5
Bet667   4
N 40 minutes ago by Bet667
Let $a,b,c,d$ be real numbers less than 2.Then prove that $\frac{a^3}{b^2+4}+\frac{b^3}{c^2+4}+\frac{c^3}{d^2+4}+\frac{d^3}{a^2+4}\le4$
4 replies
Bet667
Today at 6:54 AM
Bet667
40 minutes ago
Medians and stuff regarding it
Konigsberg   2
N an hour ago by lightsynth123
Source: SMO(O) 2014 #2
Let $ABC$ be an acute-angled triangle and let $D$, $E$, and $F$ be the midpoints of $BC$, $CA$, and $AB$ respectively. Construct a circle, centered at the orthocenter of triangle $ABC$, such that triangle $ABC$ lies in the interior of the circle. Extend $EF$ to intersect the circle at $P$, $FD$ to intersect the circle at $Q$ and $DE$ to intersect the circle at $R$. Show that $AP=BQ=CR$.
2 replies
Konigsberg
Jan 22, 2015
lightsynth123
an hour ago
interesting nt
medhimdi   0
an hour ago
Source: OFM2021 Senior P1
Let $a_1, a_2, a_3, \dots$ and $b_1, b_2, b3, \dots$ be two sequences of integers such that $a{n+2}=a_{n+1}+an$ and $b{n+2}=b_{n+1}+b_n$ for all $n\geq1$. Suppose that $a_n$ divides $b_n$ for an infinity of integers $n\geq1$. Prove that there exist an integer $c$ such that $b_n=ca_n$ for all $n\geq1$
0 replies
medhimdi
an hour ago
0 replies
Inequality from China
sqing   0
an hour ago
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.$
0 replies
sqing
an hour ago
0 replies
mathcounts state discussion
Soupboy0   44
N an hour ago by RollingPanda4616
les goo its finally april
44 replies
Soupboy0
Apr 1, 2025
RollingPanda4616
an hour ago
A problem
KhuongTrang   18
N an hour ago by KhuongTrang
Source: own
Problem. Let $a,b,c$ be positive real variables such that $a+b+c=3.$ Prove that $$\color{black}{\sqrt{2a^{2}-a+3}+\sqrt{2b^{2}-b+3}+\sqrt{2c^{2}-c+3}\le 3\sqrt{\frac{ab+bc+ca+9}{ab+bc+ca}}.}$$
18 replies
KhuongTrang
Dec 2, 2024
KhuongTrang
an hour ago
9 MATHCOUNTS STATE difficulty
Eddie_tiger   61
N 2 hours ago by DhruvJha
I personally thought the problems were much easier than last year, but I didn't really improve as much as I would of liked to improve.
61 replies
Eddie_tiger
Apr 1, 2025
DhruvJha
2 hours ago
Circle !
ComplexPhi   6
N 2 hours ago by mathbetter
Let $AB$ and $CD$ be chords in a circle of center $O$ with $A , B , C , D$ distinct , and with the lines $AB$ and $CD$ meeting at a right angle at point $E$. Let also $M$ and $N$ be the midpoints of $AC$ and $BD$ respectively . If $MN \bot OE$ , prove that $AD \parallel BC$.
6 replies
ComplexPhi
Feb 4, 2015
mathbetter
2 hours ago
How much does math help?
Dream9   5
N Mar 30, 2025 by yaxuan
Does the math many people on AOPS work for really make a large impact? I get that this is a place for math but I think I'm losing touch with my prior math skill. AMC and AIME are solving problems that have answers and just take practice but math as a job or just like an accountant doesn't need/needs a lot more than this type of math. I might switch to another stem category for college apps pathway. Also, many people who are already very good at competition math don't get good offers because there's people who are even better(note: i get the point of math isn't only college). I think if I work *hard* I'll be AIME qual but I think many people would have higher achievements with the same amount of work in another category. I think competition math really just trains for problem solving, unique thinking, and pattern recognition(aka IQ pts).
5 replies
Dream9
Mar 30, 2025
yaxuan
Mar 30, 2025
How much does math help?
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Dream9
78 posts
#1
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Does the math many people on AOPS work for really make a large impact? I get that this is a place for math but I think I'm losing touch with my prior math skill. AMC and AIME are solving problems that have answers and just take practice but math as a job or just like an accountant doesn't need/needs a lot more than this type of math. I might switch to another stem category for college apps pathway. Also, many people who are already very good at competition math don't get good offers because there's people who are even better(note: i get the point of math isn't only college). I think if I work *hard* I'll be AIME qual but I think many people would have higher achievements with the same amount of work in another category. I think competition math really just trains for problem solving, unique thinking, and pattern recognition(aka IQ pts).
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huajun78
48 posts
#2
Y by
I mean if you like doing it you should do it
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Dream9
78 posts
#3
Y by
real
#needs8characters
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ChaitraliKA
1002 posts
#4
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Quote:
I think competition math really just trains for problem solving, unique thinking, and pattern recognition(aka IQ pts).
*just* problem solving and unique thinking...

As if that's not going to be the main part of your potential stem job in the future :o
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Dream9
78 posts
#5
Y by
ChaitraliKA wrote:
Quote:
I think competition math really just trains for problem solving, unique thinking, and pattern recognition(aka IQ pts).
*just* problem solving and unique thinking...

As if that's not going to be the main part of your potential stem job in the future :o

Yes but what I meant was that since I'm already at a certain level I think maybe 10 more hrs of work will only get me a bit of useful growth in other areas.
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yaxuan
3335 posts
#6
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It really depends on the “level” of math that you already are, I think. For me, AoPS has been helping immensely. For some others, maybe not so much.
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