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Apr
8
comment Are mathematical articles on Wikipedia reliable?
@user140943 I cannot point to current errors, because I would fix them. But for example, I remember that the formula in Stewart's theorem was wrong at some time.
Apr
7
comment Are mathematical articles on Wikipedia reliable?
But there are many errors in formulas, and even worse, pages for typical first/second year courses are often correct, but very bad. (No examples, obfuscating language, etc.) Beginners' courses have to be structured very well and wikipedia cannot do that.
Apr
7
comment Are mathematical articles on Wikipedia reliable?
I like to look up mathematics on wikipedia (and mathworld), but I usually either know the result or can easily check the correctness. And contrary to a book, I can correct all the errors forever.
Apr
7
comment Show that if n divides a single Fibonacci number., then it will divide infinitely many Fibonacci numbers.
@MarioCarneiro $(F_k,F_{k+1}) \mod n$ has to repeat eventually. Since it starts out with $F_0=0$, you get 0 again and again.
Apr
7
comment Show that if n divides a single Fibonacci number., then it will divide infinitely many Fibonacci numbers.
Actually, you can do better: Any $n$ divides infinitely many Fibonacci numbers.
Mar
23
comment Perimeter of the triangle
@bigli Yes, I corrected it.
Mar
23
comment Perimeter of the triangle
Your formulas describe angle bisectors not medians.
Mar
22
comment Slope intercept equation where b is the point on x-axis?
It is correct, but you should take care not to call the number $b$ the point and of course, it does not work if $m=0$.
Feb
20
comment Proving that $\sqrt{4ab-1}=m^2$ is equivalent to $a=b$. where $a$ and $b$ are non zero integers
Your start is wrong (you did not take the square root of $q$), so it is impossible to finish your proof. Therefore, I will vote to close. If you edit your question, I will of course vote to reopen.
Feb
17
comment Prove that the product of some numbers between perfect squares is $2k^2$
The numbers where we can just use a single factor seem to form the Beatty sequence for sqrt 2 which seems quite reasonable.
Feb
14
comment Determinant of a finite-dimensional matrix in terms of trace
This answer is missing the connection to the fact that $C$ is a commutator. The question is to which degree this simplifies the expression.
Feb
10
comment How find this $\sum_{n=1}^{\infty}\frac{H^3_{n}}{n+1}(-1)^{n+1}$
The Sigma package of Carsten Schneider for Mathematica should be able to deal with a sum like this. See risc.jku.at/research/combinat/software/Sigma/index.php
Feb
10
comment How find this $a_{n},b_{n}$
I think that it would be helpful to say where it comes from. Is it a geometric problem? An approximation to a certain expression?
Feb
10
comment Purely combinatorial proof and simplification of identity involving factorials and summations
I cannot tell how you find "follows the following recurrence". Why do you multiply by 2?
Feb
10
comment Using “we have” in maths papers
This "we" includes the reader, so you should make sure that this is actually appropriate. In addition, if "we have" sounds strange, it is most likely due to the fact that it could be replaced with a more precise phrase, not due to the "we".
Feb
8
comment Show that exists a function not increasing $f:(a,b)\rightarrow\mathbb{R}$ that is continuous only over $(a,b)\setminus D$
There is both the possibility that this was accidental and the possibility that you were supposed to solve the general question with a theorem from your course and then solve the particular example with an explicit example.
Feb
7
comment Are transcendental numbers computable?
Is it obvious that it is impossible to define a real number in a way that makes it undecidable if it is computable and algebraic? In that case, it would be perfectly possible to have an algebraic number that is not computable. All the answers seem to assume that the numbers are either given by their polynomials or known to be algebraic.
Feb
4
comment Why are there so few Euclidean geometry problems that remain unsolved?
@RBarryYoung I guess that you and Asaf are the most likely to help me on this.
Feb
4
comment Why are there so few Euclidean geometry problems that remain unsolved?
@AsafKaragila I would appreciate a lot if someone could point to resources that explain why Euclidean geometry is decidable and/or projective geometry is not.
Feb
3
comment A correct proof for this pumping lemma example?
@user3130467 Where?