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k a My Retirement & New Leadership at AoPS
rrusczyk   1571
N Mar 26, 2025 by SmartGroot
I write today to announce my retirement as CEO from Art of Problem Solving. When I founded AoPS 22 years ago, I never imagined that we would reach so many students and families, or that we would find so many channels through which we discover, inspire, and train the great problem solvers of the next generation. I am very proud of all we have accomplished and I’m thankful for the many supporters who provided inspiration and encouragement along the way. I'm particularly grateful to all of the wonderful members of the AoPS Community!

I’m delighted to introduce our new leaders - Ben Kornell and Andrew Sutherland. Ben has extensive experience in education and edtech prior to joining AoPS as my successor as CEO, including starting like I did as a classroom teacher. He has a deep understanding of the value of our work because he’s an AoPS parent! Meanwhile, Andrew and I have common roots as founders of education companies; he launched Quizlet at age 15! His journey from founder to MIT to technology and product leader as our Chief Product Officer traces a pathway many of our students will follow in the years to come.

Thank you again for your support for Art of Problem Solving and we look forward to working with millions more wonderful problem solvers in the years to come.

And special thanks to all of the amazing AoPS team members who have helped build AoPS. We’ve come a long way from here:IMAGE
1571 replies
rrusczyk
Mar 24, 2025
SmartGroot
Mar 26, 2025
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k a March Highlights and 2025 AoPS Online Class Information
jlacosta   0
Mar 2, 2025
March is the month for State MATHCOUNTS competitions! Kudos to everyone who participated in their local chapter competitions and best of luck to all going to State! Join us on March 11th for a Math Jam devoted to our favorite Chapter competition problems! Are you interested in training for MATHCOUNTS? Be sure to check out our AMC 8/MATHCOUNTS Basics and Advanced courses.

Are you ready to level up with Olympiad training? Registration is open with early bird pricing available for our WOOT programs: MathWOOT (Levels 1 and 2), CodeWOOT, PhysicsWOOT, and ChemWOOT. What is WOOT? WOOT stands for Worldwide Online Olympiad Training and is a 7-month high school math Olympiad preparation and testing program that brings together many of the best students from around the world to learn Olympiad problem solving skills. Classes begin in September!

Do you have plans this summer? There are so many options to fit your schedule and goals whether attending a summer camp or taking online classes, it can be a great break from the routine of the school year. Check out our summer courses at AoPS Online, or if you want a math or language arts class that doesn’t have homework, but is an enriching summer experience, our AoPS Virtual Campus summer camps may be just the ticket! We are expanding our locations for our AoPS Academies across the country with 15 locations so far and new campuses opening in Saratoga CA, Johns Creek GA, and the Upper West Side NY. Check out this page for summer camp information.

Be sure to mark your calendars for the following events:
[list][*]March 5th (Wednesday), 4:30pm PT/7:30pm ET, HCSSiM Math Jam 2025. Amber Verser, Assistant Director of the Hampshire College Summer Studies in Mathematics, will host an information session about HCSSiM, a summer program for high school students.
[*]March 6th (Thursday), 4:00pm PT/7:00pm ET, Free Webinar on Math Competitions from elementary through high school. Join us for an enlightening session that demystifies the world of math competitions and helps you make informed decisions about your contest journey.
[*]March 11th (Tuesday), 4:30pm PT/7:30pm ET, 2025 MATHCOUNTS Chapter Discussion MATH JAM. AoPS instructors will discuss some of their favorite problems from the MATHCOUNTS Chapter Competition. All are welcome!
[*]March 13th (Thursday), 4:00pm PT/7:00pm ET, Free Webinar about Summer Camps at the Virtual Campus. Transform your summer into an unforgettable learning adventure! From elementary through high school, we offer dynamic summer camps featuring topics in mathematics, language arts, and competition preparation - all designed to fit your schedule and ignite your passion for learning.[/list]
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0 replies
jlacosta
Mar 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
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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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Problem 2
Functional_equation   15
N a few seconds ago by basilis
Source: Azerbaijan third round 2020
$a,b,c$ are positive integer.
Solve the equation:
$ 2^{a!}+2^{b!}=c^3 $
15 replies
1 viewing
Functional_equation
Jun 6, 2020
basilis
a few seconds ago
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VERY HARD MATH PROBLEM!
slimshadyyy.3.60   14
N 3 minutes ago by GreekIdiot
Let a ≥b ≥c ≥0 be real numbers such that a^2 +b^2 +c^2 +abc = 4. Prove that
a+b+c+(√a−√c)^2 ≥3.
14 replies
slimshadyyy.3.60
Yesterday at 10:49 PM
GreekIdiot
3 minutes ago
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Intersection of a cevian with the incircle
djb86   24
N 6 minutes ago by Ilikeminecraft
Source: South African MO 2005 Q4
The inscribed circle of triangle $ABC$ touches the sides $BC$, $CA$ and $AB$ at $D$, $E$ and $F$ respectively. Let $Q$ denote the other point of intersection of $AD$ and the inscribed circle. Prove that $EQ$ extended passes through the midpoint of $AF$ if and only if $AC = BC$.
24 replies
djb86
May 27, 2012
Ilikeminecraft
6 minutes ago
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Polynomials and their shift with all real roots and in common
Assassino9931   2
N 13 minutes ago by AshAuktober
Source: Bulgaria Spring Mathematical Competition 2025 11.4
We call two non-constant polynomials friendly if each of them has only real roots, and every root of one polynomial is also a root of the other. For two friendly polynomials \( P(x), Q(x) \) and a constant \( C \in \mathbb{R}, C \neq 0 \), it is given that \( P(x) + C \) and \( Q(x) + C \) are also friendly polynomials. Prove that \( P(x) \equiv Q(x) \).
2 replies
Assassino9931
4 hours ago
AshAuktober
13 minutes ago
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Impossible to search, classic graph problem
AshAuktober   0
16 minutes ago
Source: Classic
Prove that any graph $G=(V,E)$ with $|V|=|E|-1$ has at least two cycles in it.
0 replies
AshAuktober
16 minutes ago
0 replies
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Functional equation
Dadgarnia   11
N 17 minutes ago by jasperE3
Source: Iranian TST 2018, second exam day 1, problem 1
Find all functions $f:\mathbb{R}\rightarrow \mathbb{R}$ that satisfy the following conditions:
a. $x+f(y+f(x))=y+f(x+f(y)) \quad \forall x,y \in \mathbb{R}$
b. The set $I=\left\{\frac{f(x)-f(y)}{x-y}\mid x,y\in \mathbb{R},x\neq y \right\}$ is an interval.

Proposed by Navid Safaei
11 replies
Dadgarnia
Apr 15, 2018
jasperE3
17 minutes ago
J
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Geo challenge on finding simple ways to solve it
Assassino9931   2
N 19 minutes ago by Assassino9931
Source: Bulgaria Spring Mathematical Competition 2025 9.2
Let $ABC$ be an acute scalene triangle inscribed in a circle \( \Gamma \). The angle bisector of \( \angle BAC \) intersects \( BC \) at \( L \) and \( \Gamma \) at \( S \). The point \( M \) is the midpoint of \( AL \). Let \( AD \) be the altitude in \( \triangle ABC \), and the circumcircle of \( \triangle DSL \) intersects \( \Gamma \) again at \( P \). Let \( N \) be the midpoint of \( BC \), and let \( K \) be the reflection of \( D \) with respect to \( N \). Prove that the triangles \( \triangle MPS \) and \( \triangle ADK \) are similar.
2 replies
Assassino9931
5 hours ago
Assassino9931
19 minutes ago
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Easy problem
Hip1zzzil   2
N 20 minutes ago by aidan0626
$(C,M,S)$ is a pair of real numbers such that

$2C+M+S-2C^{2}-2CM-2MS-2SC=0$
$C+2M+S-3M^{2}-3CM-3MS-3SC=0$
$C+M+2S-4S^{2}-4CM-4MS-4SC=0$

Find $2C+3M+4S$.
2 replies
Hip1zzzil
4 hours ago
aidan0626
20 minutes ago
J
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Train yourself on folklore NT FE ideas
Assassino9931   2
N 32 minutes ago by bo18
Source: Bulgaria Spring Mathematical Competition 2025 9.4
Determine all functions $f: \mathbb{Z}_{>0} \to \mathbb{Z}_{>0}$ such that $f(a) + 2ab + 2f(b)$ divides $f(a)^2 + 4f(b)^2$ for any positive integers $a$ and $b$.
2 replies
Assassino9931
5 hours ago
bo18
32 minutes ago
J
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When is this well known sequence periodic?
Assassino9931   2
N 38 minutes ago by Assassino9931
Source: Bulgaria Spring Mathematical Competition 2025 12.2
Determine all values of $a_0$ for which the sequence of real numbers with $a_{n+1}=3a_n - 4a_n^3$ for all $n\geq 0$ is periodic from the beginning.
2 replies
Assassino9931
4 hours ago
Assassino9931
38 minutes ago
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Concurrence of angle bisectors
proglote   65
N 42 minutes ago by smbellanki
Source: Brazil MO #5
Let $ABC$ be an acute triangle and $H$ is orthocenter. Let $D$ be the intersection of $BH$ and $AC$ and $E$ be the intersection of $CH$ and $AB$. The circumcircle of $ADE$ cuts the circumcircle of $ABC$ at $F \neq A$. Prove that the angle bisectors of $\angle BFC$ and $\angle BHC$ concur at a point on $BC.$
65 replies
proglote
Oct 20, 2011
smbellanki
42 minutes ago
J
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Number theory
spiderman0   0
44 minutes ago
Find all n such that $3^n + 1$ is divisibly by $n^2$.
I want a solution that uses order or a solution like “let p be the least prime divisor of n”
0 replies
spiderman0
44 minutes ago
0 replies
J
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Bulgaria team selection test 2015
luutrongphuc   0
an hour ago
Find all real-coefficient polynomials of the form
\[ f(x) = x^{2n} + a_1 x^{2n-1} + \dots + a_{n-1} x^{n+1} + a_n x^n + a_{n-1} x^{n-1} + \dots + a_1 x + 1 \]that have \( 2n \) real roots and satisfy \( |a_i| \leq 2 \) for all \( i = 1, 2, \dots, n \).
0 replies
luutrongphuc
an hour ago
0 replies
J
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Angles TXA and BAC are equal
nAalniaOMliO   3
N an hour ago by Retemoeg
Source: Belarusian National Olympiad 2025
Altitudes $BE$ and $CF$ of triangle $ABC$ intersect in $H$. A perpendicular $HT$ from $H$ to $EF$ is drawn. Circumcircles $ABC$ and $BHT$ intersect at $B$ and $X$.
Prove that $\angle TXA= \angle BAC$.
3 replies
nAalniaOMliO
Friday at 8:23 PM
Retemoeg
an hour ago
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no...........................;-;
Cobedangiu   3
N Mar 27, 2025 by sqing
This issue has been posted already, I will delete it.
3 replies
Cobedangiu
Mar 27, 2025
sqing
Mar 27, 2025
J
no...........................;-;
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Reveal topic tags
inequalities
L
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Cobedangiu
24 posts
Cobedangiu
#1 h  Mar 27, 2025, 4:41 AM
Y by
This issue has been posted already, I will delete it.
This post has been edited 4 times. Last edited by Cobedangiu, Mar 27, 2025, 5:54 PM
Z K Y
The post below has been deleted. Click to close.
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lbh_qys
450 posts
lbh_qys
#2 h  Mar 27, 2025, 4:55 AM • 1 Y
Y by Cobedangiu
Note that
\[ D = \sum \left(5a^2 + \frac{4}{a}\right) = \sum \left(\frac{(a-1)^2\left(a+4-2a^2\right)}{a} + 2a^3 + 7\right) \geq \sum \left(2a^3 + 7\right) = 27, \]with equality occurring when \(a = b = c = 1\).
Z K Y
The post below has been deleted. Click to close.
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Cobedangiu
24 posts
Cobedangiu
#3 h  Mar 27, 2025, 1:16 PM
Y by
......................
This post has been edited 1 time. Last edited by Cobedangiu, Mar 27, 2025, 1:46 PM
Z K Y
The post below has been deleted. Click to close.
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sqing
41325 posts
sqing
#4 h  Mar 27, 2025, 1:34 PM
Y by
Cobedangiu wrote:
Let $a,b,c>0, a^3+b^3+c^3=3.$ Find min D(and prove)
$ D=5(a^2+b^2+c^2)+4(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}) $
https://artofproblemsolving.com/community/c6h2063664p14726104
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