ka May Highlights and 2025 AoPS Online Class Information
jlacosta0
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.
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
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Thursday, May 15 - Jul 31
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Introduction to Number Theory
Friday, May 9 - Aug 1
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Introduction to Algebra B
Tuesday, May 6 - Aug 19
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Introduction to Geometry
Sunday, May 11 - Nov 9
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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
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Thursday, Jul 24 - Jan 22
MATHCOUNTS/AMC 8 Basics
Friday, May 23 - Aug 15
Monday, Jun 2 - Aug 18
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MATHCOUNTS/AMC 8 Advanced
Sunday, May 11 - Aug 10
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AMC 10 Problem Series
Friday, May 9 - Aug 1
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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
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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
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.
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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...)
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- "Number of solutions to x²+y²=6z²"
- "Fibonacci numbers are never squares"
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[code]+"first keyword" +"second keyword"[/code]
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Some recent really bad post was:
[quote][/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.
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The above rules will be applied from next monday (5. march of 2007).
Feel free to discuss on this here.
Let be a point outside circle centered at . Tangents from to touch at . Line intersects bigger arc at .The line drawn from parallel to intersects at . Ray intersects small arc at . Prove that the circumcircle of is tangent to .
A square is filled with numbers .The numbers inside four squares is calculated,and arranged in an increasing order. Is it possible to obtain the following sequences as a result of this operation?
Alice and Bob take turns taking balloons from a box containing infinitely many balloons. In the first turn, Alice takes amount of balloons, where . Then, on his first turn, Bob takes amount of ballons where . After first turn, Alice and Bob alternately takes as many balloons as his/her partner has. Is it possible for Bob to take amount of balloons at first, such that after a finite amount of turns, one of them have a number of balloons that is a multiple of ?
This question just asks if you can factorise 12 factorial or not
Sadigly0
an hour ago
Source: Azerbaijan Junior MO 2025 P1
A teacher creates a fraction using numbers from to (including ). He writes some of the numbers on the numerator, and writes (product) between each number. Then he writes the rest of the numbers in the denominator and also writes between each number. There is at least one number both in numerator and denominator. The teacher ensures that the fraction is equal to the smallest possible integer possible.
What is this positive integer, which is also the value of the fraction?
Given quadrilateral ABCD inscribed in a circle with center O. CA:CB= DA:DB are satisfied. M is any point and d is a line parallel to MC. Radial projection M transforms A,B,D onto line d into A',B',D'. Prove that B' is the midpoint of A'D'.
is a right-angled triangle, . Draw a circle centered at with radius . Let be a point on the side , and is tangent to the circle at . The line through perpendicular to meets line at . Line meets at point . The line through parallel to meets at . Prove that .
is a right-angled triangle, . Draw a circle centered at with radius . Let be a point on the side , and is tangent to the circle at . The line through perpendicular to meets line at . Line meets at point . The line through parallel to meets at . Prove that .
Because I am a little confused with Issl's proof, for example "Let us denote the intersection of and be " (???) and "" (???) ..., I will post my solution here. However, I see that we both may have some same ideas:
Let cut the circle with center , radius again at , what we have to prove is equivalent to prove that
Let cut the circle with diameter again at , as is cyclic, hence , thus is cyclic, but as is isosceles, it is obvious that
Thus , notice that .
Using Melenaus in we get , but , so hence
Because I am a little confused with Issl's proof, for example "Let us denote the intersection of and be " (???) and "" (???) ..., I will post my solution here. However, I see that we both may have some same ideas:
Let cut the circle with center , radius again at , what we have to prove is equivalent to prove that
Let cut the circle with diameter again at , as is cyclic, hence , thus is cyclic, but as is isosceles, it is obvious that
Thus , notice that .
Using Melenaus in we get , but , so hence
Obviously you must have misunderstood the statement of this problem. According to the statement, D should be on side AC, not on AB. BTW, I make a solution with projective geometry.
Let ,,
Notice that is also tangent to the circle hence . Now,
Proof.Applying Menelaus Theorem to , we have
It hence suffices to prove
since which is exactly what we want to prove.
Hence the claim is proved and
This post has been edited 1 time. Last edited by mathaddiction, Apr 18, 2020, 8:38 AM
Let . Notice that is cyclic, and furthermore it is the nine-point circle of . But is the -antipode in , hence as is the orthocenter, is the foot of the -altitude, and thus lies on the circle too.