Stay ahead of learning milestones! Enroll in a class over the summer!

G
Topic
First Poster
Last Poster
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.

Introductory: Grades 5-10

Prealgebra 1 Self-Paced

Prealgebra 1
Tuesday, May 13 - Aug 26
Thursday, May 29 - Sep 11
Sunday, Jun 15 - Oct 12
Monday, Jun 30 - Oct 20
Wednesday, Jul 16 - Oct 29

Prealgebra 2 Self-Paced

Prealgebra 2
Wednesday, May 7 - Aug 20
Monday, Jun 2 - Sep 22
Sunday, Jun 29 - Oct 26
Friday, Jul 25 - Nov 21

Introduction to Algebra A Self-Paced

Introduction to Algebra A
Sunday, May 11 - Sep 14 (1:00 - 2:30 pm ET/10:00 - 11:30 am PT)
Wednesday, May 14 - Aug 27
Friday, May 30 - Sep 26
Monday, Jun 2 - Sep 22
Sunday, Jun 15 - Oct 12
Thursday, Jun 26 - Oct 9
Tuesday, Jul 15 - Oct 28

Introduction to Counting & Probability Self-Paced

Introduction to Counting & Probability
Thursday, May 15 - Jul 31
Sunday, Jun 1 - Aug 24
Thursday, Jun 12 - Aug 28
Wednesday, Jul 9 - Sep 24
Sunday, Jul 27 - Oct 19

Introduction to Number Theory
Friday, May 9 - Aug 1
Wednesday, May 21 - Aug 6
Monday, Jun 9 - Aug 25
Sunday, Jun 15 - Sep 14
Tuesday, Jul 15 - Sep 30

Introduction to Algebra B Self-Paced

Introduction to Algebra B
Tuesday, May 6 - Aug 19
Wednesday, Jun 4 - Sep 17
Sunday, Jun 22 - Oct 19
Friday, Jul 18 - Nov 14

Introduction to Geometry
Sunday, May 11 - Nov 9
Tuesday, May 20 - Oct 28
Monday, Jun 16 - Dec 8
Friday, Jun 20 - Jan 9
Sunday, Jun 29 - Jan 11
Monday, Jul 14 - Jan 19

Paradoxes and Infinity
Mon, Tue, Wed, & Thurs, Jul 14 - Jul 16 (meets every day of the week!)

Intermediate: Grades 8-12

Intermediate Algebra
Sunday, Jun 1 - Nov 23
Tuesday, Jun 10 - Nov 18
Wednesday, Jun 25 - Dec 10
Sunday, Jul 13 - Jan 18
Thursday, Jul 24 - Jan 22

Intermediate Counting & Probability
Wednesday, May 21 - Sep 17
Sunday, Jun 22 - Nov 2

Intermediate Number Theory
Sunday, Jun 1 - Aug 24
Wednesday, Jun 18 - Sep 3

Precalculus
Friday, May 16 - Oct 24
Sunday, Jun 1 - Nov 9
Monday, Jun 30 - Dec 8

Advanced: Grades 9-12

Olympiad Geometry
Tuesday, Jun 10 - Aug 26

Calculus
Tuesday, May 27 - Nov 11
Wednesday, Jun 25 - Dec 17

Group Theory
Thursday, Jun 12 - Sep 11

Contest Preparation: Grades 6-12

MATHCOUNTS/AMC 8 Basics
Friday, May 23 - Aug 15
Monday, Jun 2 - Aug 18
Thursday, Jun 12 - Aug 28
Sunday, Jun 22 - Sep 21
Tues & Thurs, Jul 8 - Aug 14 (meets twice a week!)

MATHCOUNTS/AMC 8 Advanced
Sunday, May 11 - Aug 10
Tuesday, May 27 - Aug 12
Wednesday, Jun 11 - Aug 27
Sunday, Jun 22 - Sep 21
Tues & Thurs, Jul 8 - Aug 14 (meets twice a week!)

AMC 10 Problem Series
Friday, May 9 - Aug 1
Sunday, Jun 1 - Aug 24
Thursday, Jun 12 - Aug 28
Tuesday, Jun 17 - Sep 2
Sunday, Jun 22 - Sep 21 (1:00 - 2:30 pm ET/10:00 - 11:30 am PT)
Monday, Jun 23 - Sep 15
Tues & Thurs, Jul 8 - Aug 14 (meets twice a week!)

AMC 10 Final Fives
Sunday, May 11 - Jun 8
Tuesday, May 27 - Jun 17
Monday, Jun 30 - Jul 21

AMC 12 Problem Series
Tuesday, May 27 - Aug 12
Thursday, Jun 12 - Aug 28
Sunday, Jun 22 - Sep 21
Wednesday, Aug 6 - Oct 22

AMC 12 Final Fives
Sunday, May 18 - Jun 15

AIME Problem Series A
Thursday, May 22 - Jul 31

AIME Problem Series B
Sunday, Jun 22 - Sep 21

F=ma Problem Series
Wednesday, Jun 11 - Aug 27

WOOT Programs
Visit the pages linked for full schedule details for each of these programs!


MathWOOT Level 1
MathWOOT Level 2
ChemWOOT
CodeWOOT
PhysicsWOOT

Programming

Introduction to Programming with Python
Thursday, May 22 - Aug 7
Sunday, Jun 15 - Sep 14 (1:00 - 2:30 pm ET/10:00 - 11:30 am PT)
Tuesday, Jun 17 - Sep 2
Monday, Jun 30 - Sep 22

Intermediate Programming with Python
Sunday, Jun 1 - Aug 24
Monday, Jun 30 - Sep 22

USACO Bronze Problem Series
Tuesday, May 13 - Jul 29
Sunday, Jun 22 - Sep 1

Physics

Introduction to Physics
Wednesday, May 21 - Aug 6
Sunday, Jun 15 - Sep 14
Monday, Jun 23 - Sep 15

Physics 1: Mechanics
Thursday, May 22 - Oct 30
Monday, Jun 23 - Dec 15

Relativity
Mon, Tue, Wed & Thurs, Jun 23 - Jun 26 (meets every day of the week!)
0 replies
jlacosta
May 1, 2025
0 replies
Inequality
MathsII-enjoy   7
N 4 minutes ago by sqing
A interesting problem generalized :-D
7 replies
MathsII-enjoy
Saturday at 1:59 PM
sqing
4 minutes ago
F.E....can you solve it?
Jackson0423   0
25 minutes ago
Find all functions \( f : \mathbb{R} \to \mathbb{R} \) such that
\[
f\left(\frac{x^2 - f(x)}{f(x) - 1}\right) = x
\]for all real numbers \( x \) satisfying \( f(x) \neq 1 \).
0 replies
Jackson0423
25 minutes ago
0 replies
Functional equation
Math-wiz   25
N an hour ago by Adywastaken
Source: IMOC SL A1
Find all functions $f:\mathbb{R}\to\mathbb{R}$ such that for all $x,y\in\mathbb{R}$,
$$f(xy+f(x))=f(xf(y))+x$$
25 replies
Math-wiz
Dec 15, 2019
Adywastaken
an hour ago
Nice numer theory
GeoArt   5
N an hour ago by Primeniyazidayi
$p$ is a prime number, $m, x, y$ are natural numbers ($m, x, y > 1$). It is known that $\frac{x^p + y^p}{2}$ $=$ $(\frac{x+y}{2} )^m$. Prove that $p = m$.
5 replies
GeoArt
Jan 7, 2021
Primeniyazidayi
an hour ago
IOQM 2022-23 P-7
lifeismathematics   2
N 2 hours ago by Adywastaken
Find the number of ordered pairs $(a,b)$ such that $a,b \in \{10,11,\cdots,29,30\}$ and
$\hspace{1cm}$ $GCD(a,b)+LCM(a,b)=a+b$.
2 replies
lifeismathematics
Oct 30, 2022
Adywastaken
2 hours ago
Inequalities
sqing   7
N 3 hours ago by sqing
Let $ a,b,c>0 $ and $ a+b\leq 16abc. $ Prove that
$$ a+b+kc^3\geq\sqrt[4]{\frac{4k} {27}}$$$$ a+b+kc^4\geq\frac{5} {8}\sqrt[5]{\frac{k} {2}}$$Where $ k>0. $
$$ a+b+3c^3\geq\sqrt{\frac{2} {3}}$$$$ a+b+2c^4\geq \frac{5} {8}$$
7 replies
sqing
Yesterday at 12:46 PM
sqing
3 hours ago
Inequalities
sqing   10
N 4 hours ago by sqing
Let $a,b,c> 0$ and $\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=1.$ Prove that
$$  (1-abc) (1-a)(1-b)(1-c)  \ge 208 $$$$ (1+abc) (1-a)(1-b)(1-c)  \le -224 $$$$(1+a^2b^2c^2) (1-a)(1-b)(1-c)  \le -5840 $$
10 replies
sqing
Jul 12, 2024
sqing
4 hours ago
China MO 1996 p1
math_gold_medalist28   1
N 4 hours ago by MathsII-enjoy
Let ABC be a triangle with orthocentre H. The tangent lines from A to the circle with diameter BC touch this circle at P and Q. Prove that H, P and Q are collinear.
1 reply
math_gold_medalist28
May 2, 2025
MathsII-enjoy
4 hours ago
If it is an integer then perfect square
Ecrin_eren   1
N 4 hours ago by Pal702004


"Let a, b, c, d be non-zero digits, and let abcd and dcba represent four-digit numbers.

Show that if the number abcd / dcba is an integer, then that integer is a perfect square."



1 reply
Ecrin_eren
May 1, 2025
Pal702004
4 hours ago
A Collection of Good Problems from my end
SomeonecoolLovesMaths   6
N 5 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
6 replies
SomeonecoolLovesMaths
Yesterday at 8:16 AM
SomeonecoolLovesMaths
5 hours ago
parallelogram in a tetrahedron
vanstraelen   0
Today at 6:43 AM
Given a tetrahedron $ABCD$ and a plane $\mu$, parallel with the edges $AC$ and $BD$.
$AB \cap \mu=P$.
a) Prove: the intersection of the tetrahedron with the plane is a parallelogram.
b) If $\left|AC\right|=14,\left|BD\right|=7$ and $\frac{\left|PA\right|}{\left|PB\right|}=\frac{3}{4}$,
calculates the lenghts of the sides of this parallelogram.
0 replies
vanstraelen
Today at 6:43 AM
0 replies
Arithmetic Series and Common Differences
4everwise   6
N Today at 2:12 AM by epl1
For each positive integer $k$, let $S_k$ denote the increasing arithmetic sequence of integers whose first term is $1$ and whose common difference is $k$. For example, $S_3$ is the sequence $1,4,7,10,...$. For how many values of $k$ does $S_k$ contain the term $2005$?
6 replies
4everwise
Nov 10, 2005
epl1
Today at 2:12 AM
find number of elements in H
Darealzolt   0
Today at 1:50 AM
If \( H \) is the set of positive real solutions to the system
\[
x^3 + y^3 + z^3 = x + y + z
\]\[
x^2 + y^2 + z^2 = xyz
\]then find the number of elements in \( H \).
0 replies
Darealzolt
Today at 1:50 AM
0 replies
old problem from an open contest
Darealzolt   0
Today at 1:41 AM
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
\[
\frac{ab}{2015} - a + b.
\]
0 replies
Darealzolt
Today at 1:41 AM
0 replies
Trigonometry Problems Collection
Amir Hossein   24
N Apr 13, 2017 by Gaurav123
See the attachment. :)

This is a nice collection of trigonometry problems. I searched but didn't find a nice collection about trigonometry, so searched trigonometry problems posted on AoPS and made this file. :)
24 replies
Amir Hossein
Feb 16, 2011
Gaurav123
Apr 13, 2017
Trigonometry Problems Collection
G H J
G H BBookmark kLocked kLocked NReply
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Amir Hossein
5452 posts
#1 • 28 Y
Y by ShahinH, lafius, ahaanomegas, fireonice18, StudentIV, AdithyaBhaskar, m1234567, Taekyukim02, Severus, Uros, mathleticguyyy, fjm30, hansduran0123, Adventure10, and 14 other users
See the attachment. :)

This is a nice collection of trigonometry problems. I searched but didn't find a nice collection about trigonometry, so searched trigonometry problems posted on AoPS and made this file. :)
Attachments:
Trigonometry Problems - Amir Hossein Parvardi.pdf (87kb)
50TRIG.tex (10kb)
This post has been edited 1 time. Last edited by Amir Hossein, Nov 21, 2017, 9:49 AM
Reason: Added the TeX file.
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Potla
1886 posts
#2 • 3 Y
Y by Adventure10, Mango247, and 1 other user
As usual, you are really amazing, Amir! Thanks a lot for this file, I am sure it will be helpful in our school curriculum and many competitive exams!

Again, thanks a lot for posting this useful file. :)
This post has been edited 1 time. Last edited by Potla, Feb 17, 2011, 3:48 AM
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
mahanmath
1354 posts
#3 • 4 Y
Y by Adventure10, Mango247, and 2 other users
Many thanks Amir :o !
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
sindennisz
152 posts
#4 • 3 Y
Y by Adventure10, Mango247, and 1 other user
Never seen a better collection....thank you!

sindennisz
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
1=2
4594 posts
#5 • 2 Y
Y by Adventure10 and 1 other user
Thanks, I needed this! :D
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Goutham
3130 posts
#6 • 2 Y
Y by Adventure10 and 1 other user
Thanks a lot, Amir.
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
AndrewTom
12750 posts
#7 • 3 Y
Y by Adventure10, Mango247, and 1 other user
Many thanks, amparvardi.
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
goodar2006
1347 posts
#8 • 3 Y
Y by Adventure10, Mango247, and 1 other user
Thanks Amir. Nice job! :)
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
sayak38kolay
195 posts
#9 • 2 Y
Y by Adventure10 and 1 other user
Thanks a lot amparvardi...
:lol:
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
omar123
2 posts
#10 • 2 Y
Y by Adventure10 and 1 other user
Thanks a lot amparvardi for this nice collection
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
applepi2000
2226 posts
#11 • 1 Y
Y by Adventure10
This is incredible! Thanks so much, ampvardi!
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Jason27603
629 posts
#12 • 3 Y
Y by Adventure10, Mango247, and 1 other user
Thank you!
Do you have a solutions file for this?
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Amir Hossein
5452 posts
#13 • 3 Y
Y by Adventure10, Mango247, and 1 other user
Thank you all for your appreciation. :)
Jason27603 wrote:
Thank you!
Do you have a solutions file for this?

I just searched and found them on AoPS, but some of the problems does not have solutions on the site, so you may post them on forums (after searching, of course).
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
siddharthanand
282 posts
#14 • 3 Y
Y by Adventure10, Mango247, and 1 other user
amparvardi wrote:
I just searched and found them on AoPS, but some of the problems does not have solutions on the site, so you may post them on forums (after searching, of course).

hey amir , problems after 40 are exclusive to series marathon and the rest questions are brilliant . hoping to find some solutions other than the link $!$
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Amir Hossein
5452 posts
#15 • 3 Y
Y by Adventure10, Mango247, and 1 other user
If you're interested to see some solutions, here you can post your solutions to the problems :).
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
applepi2000
2226 posts
#16 • 2 Y
Y by Adventure10, Mango247
3
More later.
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Amir Hossein
5452 posts
#17 • 3 Y
Y by Adventure10, Mango247, and 1 other user
@applepi2000: but no, $\sqrt{\cos^2 4 \theta} = \pm \cos 4 \theta.$
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
applepi2000
2226 posts
#18 • 1 Y
Y by Adventure10
Sorry, forgot that case -_-

Anyway, I'll try other ones then:
4
5
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
mrmohamed
169 posts
#19 • 2 Y
Y by Adventure10, Mango247
amparvardi wrote:
See the attachment. :)

This is a nice collection of trigonometry problems. I searched but didn't find a nice collection about trigonometry, so searched trigonometry problems posted on AoPS and made this file. :)
many thanks for you Amir great post
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Ligouras
826 posts
#20 • 1 Y
Y by Adventure10
Thanks a lot, Amir
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
brandbest1
259 posts
#21 • 1 Y
Y by Adventure10
HUGE BUMP

Any solutions to 1 and 2?
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
LzuTao
6 posts
#22 • 2 Y
Y by Adventure10, Mango247
Amir Hossein wrote:
See the attachment. :)

This is a nice collection of trigonometry problems. I searched but didn't find a nice collection about trigonometry, so searched trigonometry problems posted on AoPS and made this file. :)

Thanks Amir, but where did you find them? I have solutions for some problems.
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
nikolapavlovic
1246 posts
#23 • 2 Y
Y by Adventure10, Mango247
21
very nice article
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
AdithyaBhaskar
652 posts
#24 • 2 Y
Y by Adventure10, Mango247
Nice job! Thanks. :D
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
Gaurav123
1 post
#25 • 1 Y
Y by Adventure10
Can I get a book in pdf , what was available in your data base.
Z K Y
N Quick Reply
G
H
=
a