Waleed Khan
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 Apr 26 comment Can an odd number $n$ divide $2^n-1$? Of course there is the case $n = 1$, but presumably you meant other than that. Mar 14 awarded Editor Mar 14 revised Triple integral of $r^{2}e^{ir\cos\theta}\sin\theta \,dr\,d\theta \,d\phi$ used \cos, \sin, \cdot Mar 14 suggested approved edit on Triple integral of $r^{2}e^{ir\cos\theta}\sin\theta \,dr\,d\theta \,d\phi$ Mar 14 suggested rejected edit on Convergence Theory Mar 14 comment Graphing equations If you know it's a polynomial you could find its degree, choose that many points, and interpolate a polynomial going through those points. But that doesn't sound like pre-calculus. Mar 14 awarded Critic Mar 14 comment Currently, what is the largest publicly known prime number such that all prime numbers less than it are known? For very large primes, I believe that probabilistic approaches are used to verify prime-ness. So I think that it may be possible that we can get faster the $\mathcal{O}\left(\frac{n}{\log n}\right)$ bound at the expense of accuracy, which we can rectify by later verifying the prime with another computer. Mar 14 awarded Commentator Mar 14 comment What's the probability of creating a Hello World Program? @Jatt You can have more or less any amount of whitespace between keywords like public, class, etc., so it's somewhat larger, but not significantly so. Though you could try another language — as the joke goes, “I once piped /dev/random into Perl and got a web server”. Mar 14 comment Currently, what is the largest publicly known prime number such that all prime numbers less than it are known? I think there are faster sieves, like the Sieve of Atkin. Mar 14 comment What's the probability of creating a Hello World Program? @arbautjc I think that the printable characters total $127 - 32$, plus up to two for newlines (since Windows uses \r\n), so you'd have $\frac{1}{96^{127-32+2}}$, not $\frac{1}{96^{128}}$. Mar 14 comment Ultrafilters on $\omega$ and lower/upper density @BrianM.Scott I didn't think it was so obvious 28 minutes ago. Mar 14 answered On prime numbers Mar 14 comment On prime numbers Of course, large Mersenne primes would be ridiculously easy to find if you could just take 2 to the last known Mersenne prime and subtract 1. Mar 14 comment Ultrafilters on $\omega$ and lower/upper density The lack of question marks. These are all statements. Mar 14 comment Ultrafilters on $\omega$ and lower/upper density While I admit I don't know this subject, I don't see a question here. Do you have to prove that there's an ultrafilter on $\omega$ such that every $A \in \mathscr{U}$ has a positive upper density? Mar 14 awarded Teacher Mar 14 comment Question about taylor expansion $f'(x) \le M$ or $f(x) \le M$? Mar 14 answered (Probability Space) Shouldn't $\mathcal{F}$ always equal the power set of $\Omega$?