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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.

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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]
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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
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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
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Saxon Math
Thayaden   8
N 2 minutes ago by awesometriangles
A qustion in the form of this is queryied,
Solve,
$$x^0-3x+4=1$$they state the sloution is $\frac43$ although I dont think its solavable as it relys on the un-assumable asumption that $x\neq 0$. Thoughts?
8 replies
+2 w
Thayaden
19 minutes ago
awesometriangles
2 minutes ago
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Mathcounts Nationals Roommate Search
iwillregretthisnamelater   27
N 16 minutes ago by Soupboy0
Does anybody want to be my roommate at nats? Every other qualifier in my state is female. :sob:
Respond quick pls i gotta submit it in like a couple of hours.
27 replies
iwillregretthisnamelater
Mar 31, 2025
Soupboy0
16 minutes ago
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2025 MATHCOUNTS State Hub
SirAppel   553
N 21 minutes ago by ethan2011
Previous Years' "Hubs": (2022) (2023) (2024)Please Read

Now that it's April and we're allowed to discuss ...
[list=disc]
[*] CA: 43 (45 44 43 43 43 42 42 41 41 41)
[*] NJ: 43 (45 44 44 43 39 42 40 40 39 38) *
[*] NY: 42 (43 42 42 42 41 40)
[*] TX: 42 (43 43 43 42 42 40 40 38 38 38)
[*] MA: 41 (45 43 42 41)
[*] WA: 41 (41 45 42 41 41 41 41 41 41 40) *
[*]VA: 40 (41 40 40 40)
[*] FL: 39 (42 41 40 39 38 37 37)
[*] IN: 39 (41 40 40 39 36 35 35 35 34 34)
[*] NC: 39 (42 42 41 39)
[*] IL: 38 (41 40 39 38 38 38)
[*] OR: 38 (44 40? 38 38)
[*] PA: 38 (41 40 40 38 38 37 36 36 34 34) *
[*] MD: 37 (43 39 39 37 37 37)
[*] AZ: 36 (40? 39? 39 36)
[*] CT: 36 (44 38 38 36 35 35 34 34 34 33 33)
[*] MI: 36 (39 41 41 36 37 37 36 36 36 36) *
[*] MN: 36 (40 36 36 36 35 35 35 34)
[*] CO: 35 (41 37 37 35 35 35 ?? 31 31 30) *
[*] GA: 35 (38 37 36 35 34 34 34 34 34 33)
[*] OH: 35 (41 37 36 35)
[*] AR: 34 (46 45 35 34 33 31 31 31 29 29)
[*] NV: 34 (41 38 ?? 34)
[*] TN: 34 (38 ?? ?? 34)
[*] WI: 34 (40 37 37 34 35 30 28 29 29 29) *
[*] HI: 32 (35 34 32 32)
[*] NH: 31 (42 35 33 31 30)
[*] DE: 30 (34 33 32 30 30 29 28 27 26? 24)
[*] SC: 30 (33 33 31 30)
[*] IA: 29 (33 30 31 29 29 29 29 29 29 29 29 29) *
[*] NE: 28 (34 30 28 28 27 27 26 26 25 25)
[*] SD: 22 (30 29 24 22 22 22 21 21 20 20)
[/list]
Cutoffs Unknown

* means that CDR is official in that state.

Notes

For those asking about the removal of the tiers, I'd like to quote Jason himself:
[quote=peace09]
learn from my mistakes
[/quote]

Help contribute by sharing your state's cutoffs!
553 replies
SirAppel
Apr 1, 2025
ethan2011
21 minutes ago
J
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real math problems
Soupboy0   56
N an hour ago by SpeedCuber7
Ill be posting questions once in a while. Here's the first question:

What fraction of numbers from $1$ to $1000$ have the digit $7$ and are divisible by $3$?
56 replies
Soupboy0
Mar 25, 2025
SpeedCuber7
an hour ago
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24 Aug FE problem
nicky-glass   3
N an hour ago by pco
Source: Baltic Way 1995
$f:\mathbb R\setminus \{0\} \to \mathbb R$
(i) $f(1)=1$,
(ii) $\forall x,y,x+y \neq 0:f(\frac{1}{x+y})=f(\frac{1}{x})+f(\frac{1}{y}) : P(x,y)$
(iii) $\forall x,y,x+y \neq 0:(x+y)f(x+y)=xyf(x)f(y) :Q(x,y)$
$f=?$
3 replies
nicky-glass
Aug 24, 2016
pco
an hour ago
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Simply equation but hard
giangtruong13   1
N an hour ago by anduran
Find all integer pairs $(x,y)$ satisfy that: $$(x^2+y)(y^2+x)=(x-y)^3$$
1 reply
giangtruong13
2 hours ago
anduran
an hour ago
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Number Theory
AnhQuang_67   0
an hour ago
Find all pairs of positive integers $(m,n)$ satisfying $2^m+21^n$ is a perfect square
0 replies
AnhQuang_67
an hour ago
0 replies
J
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Hard Polynomial Problem
MinhDucDangCHL2000   1
N 2 hours ago by Tung-CHL
Source: IDK
Let $P(x)$ be a polynomial with integer coefficients. Suppose there exist infinitely many integer pairs $(a,b)$ such that $P(a) + P(b) = 0$. Prove that the graph of $P(x)$ is symmetric about a point (i.e., it has a center of symmetry).
1 reply
MinhDucDangCHL2000
3 hours ago
Tung-CHL
2 hours ago
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IMO LongList 1985 CYP2 - System of Simultaneous Equations
Amir Hossein   13
N 2 hours ago by cubres
Solve the system of simultaneous equations
\[\sqrt x - \frac 1y - 2w + 3z = 1,\]\[x + \frac{1}{y^2} - 4w^2 - 9z^2 = 3,\]\[x \sqrt x - \frac{1}{y^3} - 8w^3 + 27z^3 = -5,\]\[x^2 + \frac{1}{y^4} - 16w^4 - 81z^4 = 15.\]
13 replies
Amir Hossein
Sep 10, 2010
cubres
2 hours ago
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Centroid Distance Identity in Triangle
zeta1   5
N 2 hours ago by DottedCaculator
Let M be any point inside triangle ABC, and let G be the centroid of triangle ABC. Prove that:

\[ |MA|^2 + |MB|^2 + |MC|^2 = |GA|^2 + |GB|^2 + |GC|^2 + 3|MG|^2 \]
5 replies
zeta1
5 hours ago
DottedCaculator
2 hours ago
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Numbers not power of 5
Kayak   34
N 2 hours ago by cursed_tangent1434
Source: Indian TST D1 P2
Show that there do not exist natural numbers $a_1, a_2, \dots, a_{2018}$ such that the numbers \[ (a_1)^{2018}+a_2, (a_2)^{2018}+a_3, \dots, (a_{2018})^{2018}+a_1 \]are all powers of $5$

Proposed by Tejaswi Navilarekallu
34 replies
Kayak
Jul 17, 2019
cursed_tangent1434
2 hours ago
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Number Theory Chain!
JetFire008   58
N 2 hours ago by Primeniyazidayi
I will post a question and someone has to answer it. Then they have to post a question and someone else will answer it and so on. We can only post questions related to Number Theory and each problem should be more difficult than the previous. Let's start!

Question 1
58 replies
JetFire008
Apr 7, 2025
Primeniyazidayi
2 hours ago
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Silly Sequences
whatshisbucket   25
N 2 hours ago by bin_sherlo
Source: ELMO 2018 #2, 2018 ELMO SL N3
Consider infinite sequences $a_1,a_2,\dots$ of positive integers satisfying $a_1=1$ and $$a_n \mid a_k+a_{k+1}+\dots+a_{k+n-1}$$for all positive integers $k$ and $n.$ For a given positive integer $m,$ find the maximum possible value of $a_{2m}.$

Proposed by Krit Boonsiriseth
25 replies
whatshisbucket
Jun 28, 2018
bin_sherlo
2 hours ago
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Divisibility NT FE
CHESSR1DER   12
N 3 hours ago by internationalnick123456
Source: Own
Find all functions $f$ $N \rightarrow N$ such for any $a,b$:
$(a+b)|a^{f(b)} + b^{f(a)}$.
12 replies
CHESSR1DER
Monday at 7:07 PM
internationalnick123456
3 hours ago
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MOP Qual
RabtejKalra   3
N Mar 28, 2025 by Existing_Human1
I'm in fifth grade and got an 18 on AMC 8, and 72 on the 10B. What should my score trend look like over the next 4-5 years to maybe make MOP. Just so that I have a pathway to compare it to.
3 replies
RabtejKalra
Mar 28, 2025
Existing_Human1
Mar 28, 2025
J
MOP Qual
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Reveal topic tags
AMC 8
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RabtejKalra
63 posts
RabtejKalra
#1 h  Mar 28, 2025, 11:05 PM
Y by
I'm in fifth grade and got an 18 on AMC 8, and 72 on the 10B. What should my score trend look like over the next 4-5 years to maybe make MOP. Just so that I have a pathway to compare it to.
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hashbrown2009
164 posts
hashbrown2009
#2 h  Mar 28, 2025, 11:11 PM
Y by
That's relatively good.
You would probably make AIME in 6th grade and JMO in 9th and perhaps USAMO then MOP in 11th or 10th.
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ethan2011
275 posts
ethan2011
#3 h  Mar 28, 2025, 11:33 PM
Y by
RabtejKalra wrote:
I'm in fifth grade and got an 18 on AMC 8, and 72 on the 10B. What should my score trend look like over the next 4-5 years to maybe make MOP. Just so that I have a pathway to compare it to.

i also got a 72 on 10B in 5th grade, AIME in 6th, and JMO in 7th and 8th
i predict that u can also get this score trend if u work hard enough, and u can potentially MOP by 9th then
gj on ur math journey
This post has been edited 1 time. Last edited by ethan2011, Mar 28, 2025, 11:33 PM
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Existing_Human1
208 posts
Existing_Human1
#4 h  Mar 28, 2025, 11:57 PM
Y by
What about me. Didn't make AIME by 1-2 questions in 8th grade, but 43 on chapter.
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