AoPS Wiki:AoPS-Mathlinks Rules and Tips

Mathematical Discussion

The Art of Problem Solving Forum & MathLinks are a shared community for discussing mathematical problems on various levels. You can share problems with others, solve others' problems, create your own problems and post them, and more.

Posting problems on AoPS/MathLinks

Posting problems

If you want to post a new problem, post it in a new topic. If you have several problems to post, post every problem in a new topic.

Discussing different problems in one topic leads to confusion.

Please double check your problem for mistakes. A simple typo in a formula can make a problem incomprehensible.

Please also give your topic a useful name. Names should describe something. It is better to write names like "prove concurrency in a right-angled triangle", "a^4+b^4+c^4\geq a^3b+b^3c+c^3a", "a^2+b^2=20c^2", "f(xf(y))f(y)=yf(xy)" than the following ones: "hard geometry", "please help me!!", "what to do with this one?", "don't know how to solve it".

Where to post

There are different forums to post problems in.

If you have a problem, you have to choose the right forum according to its level:

• High School Basics is for problems that would be considered part of the standard U.S. high school curriculum. This generally means algebra and geometry. Very easy combinatorics or number theory problems would also be appropriate for this forum. Problems in this forum should be at the SAT or easy AMC 10/12 level. Problems in this forum should usually not require complicated proofs.
• Intermediate Topics is for problems that are harder than "basic", but not yet approaching the olympiad level. Some examples are harder AMC 10/12 problems or easier AIME problems. Generally these will be problems that do not require complicated proofs.
• Pre-Olympiad is for problems slightly under the olympiad level and for very easy olympiad problems. Many problems at this level will require proofs.
• Olympiad Section is for olympiad-level problems.
  • Olympiad-level means the level of the IMO, of IMO shortlists, of the USAMO or the Baltic Way mathematical competition.
• College Playground is a special forum for problems that require knowledge that is usually not given in schools - for instance, linear algebra, calculus, topology.

The Olympiad Section is subdivided into subforums:

• Algebra
• Combinatorics
• Geometry
• Inequalities
• Number Theory

Decide which topic your problem belongs to, and post it into the respective subforum.

Each of these subforums is subdivided into subsubforums:

• Unsolved Problems: Post your problem here if you don't know its solution and you are searching for it, but you know there is a solution (e.g. because the problem was given at an olympiad).
• Proposed & Own Problems: Post your problem here if you know the solution and you want to share the problem with others.
• Open Questions: Post your problem here if it is a conjecture, i.e. you don't have its solution and you don't even know whether it has ever been solved.
• Solved Problems: This is the archive for former "Unsolved" problems which were then solved. Don't post new problems here, it's an archive!
• Theorems and Formulas: This is for important and useful theorems.

How to post

All posts should:

• be correct: strive for no typos and errors, and double-check your message before you post it. If you find a typo after posting, please edit your message to correct it.
• be readable: use LaTeX (see below) on your mathematical statements. Write in complete sentences.
• be interesting and/or helpful for someone: a reply that just contains "it's easy" or "I solved it" interests no one. Every post should have some content.
• don't quote whole pages just to make a one-line answer. You don't need to quote previous response(s) unless you are responding to a specific portion of someone's earlier post.
• be appropriate and on-topic: be nice, don't shout or insult, and post only things that fit the topic.
• always practice good netiquette.

Posting solutions

Wherever you see a problem on the forum, you can post a solution to it if you want.

The solution needs not be 100% detailed, but it must be understandable. Posts consisting only of words like "The problem is easy" or "Cauchy-Schwarz solves it" have no value and may be deleted.

Please post solutions at your level! If you are an Olympiad-level student, do not post solutions in the "High School Basics" forum -- leave those problems for students at that level. However, you may comment (politely, of course!) on other students' solutions, and/or provide hints if the students seem stuck.

Other cases of posting

You are not limited to posting and solving problems. You can write whatever you want, assumed that it is useful and relevant to the forum. For instance, you can generalize problems, point out mistakes in others' proofs, ask questions about others' solutions, simplify others' solutions, and so on. But please note that the mathematical sections of AoPS/MathLinks are for mathematical discussion only. For non-mathematical discussions, there are the Round Table, the Games & Fun Factory and some more. Non-mathematical discussions in mathematical sections of AoPS/MathLinks can be considered offtopic and removed.

Running competitions and homework

This may be obvious, but: Don't post problems from running homework competitions! You are supposed to solve them on your own, so making others solve them for you is cheating!

If you have post-school or university homework problems, please indicate that your problems are homework. In most cases, you will get no complete solutions, but hints and other help. You can achieve this by typing <hide>text</hide> to prevent spoiling answers!

Using LaTeX

LaTeX makes it possible to include formulas in your posts. For instance, by writing

$a^2 + a^3b$

you get , and by writing

$\frac{a}{b} + 2! = 3^{10}$

you get . Learning LaTeX is very easy by this short tutorial and by testing it out on the forum. Testing can be done in the Test Forum.

Searching on the forum

Before you post a new problem, you should ask yourself whether this problem has already been discussed on AoPS/MathLinks. You can find this out using two functions of the forum:

The Search function helps you find topics in the forum by some keywords. For instance, if your problem is from the USAMO 2002, you can type "USAMO 2002" into the search field. If your problem is about a triangle, its incircle and some altitudes, you can try typing "triangle incircle altitude*" into the search field (the * in "altitude*" is there to find both "altitude" and "altitudes"). You can also restrict the search to some subforums if necessary, so if you look for a Number Theory problem, try restricting the search to the Number Theory subforum if at first there were too many results.

The Resources section contains lists of problems of several olympiads. If you know what competition your problem is from, you can look up this competition in the Resources section. If you find your problem there, click on the problem number on the left of the page, and you get a thread with this problem.

You are not supposed to spend half an hour searching for your problem on AoPS/MathLinks, but it is helpful if you try it at least once, better twice.

See also

• Main Page