Activity for r~~
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #290318 |
Your claim is correct as written, I think.
It is the case that for most numbers, it is unknown if the number is normal. (That is, for a real number between 0 and 1 chosen uniformly, the probability that we know whether it is normal or not is 0.)
It is also the case that we know that most number... (more) |
— | 5 months ago |
| Comment | Post #290305 |
But from the Atlas link it seems that unshackling yourself from a specific geometry unlocks *thousands* of new regular 4-polytopes. I don't see how this answers the question. You assert in your answer that most of those linked polytopes aren't regular but can you support that claim at all? The Atlas ... (more) |
— | 5 months ago |
| Comment | Post #290196 |
You probably mean to specify that M is a *connected* n-dimensional compact manifold; the nth Betti number is in fact the number of connected components if M is orientable. (more) |
— | 5 months ago |
| Comment | Post #290305 |
> They are the only ones aside from the 6 convex Euclidean 4-polytopes.
This can't be true; there are also 5 regular projective 4-polytopes, for example (hemi-tesseract through hemi-600-cell). I don't have deep expertise here but I don't know of any reason why the linked list from the Atlas of Sma... (more) |
— | 5 months ago |
| Comment | Post #289826 |
> because what the code does is pick a random number with random.randint() for each candidate, and not have a fixed total population size.
So instead of simulating each voter making a random choice, you're choosing the number of voters for each candidate from a uniform distribution? This has a sim... (more) |
— | 7 months ago |
| Comment | Post #289826 |
Does your code vary the population size at all? You should definitely see a change in your observed probability for the same $n$ if so, which means that a formula expressed only in terms of $n$ can't be right. (more) |
— | 7 months ago |
| Comment | Post #289671 |
Wow, you seem pretty twisted up over the purpose of this site. This isn't a social media site. We are collaboratively building a public repository of knowledge here. Your submissions aren't primarily acts of personal expression; they are primarily bricks in an edifice of which we are all custodians. ... (more) |
— | 8 months ago |
| Comment | Post #288820 |
> One obvious criterion is that all the open squares be connected. If a set of squares are "walled off" with mines, then there is no way to get clues to the mines inside from the outside.
The total number of mines is known, so if there are multiple disconnected open regions but all but one of them... (more) |
— | 10 months ago |
| Comment | Post #288168 |
Do you intend the mod to be outside the sum or inside it—i.e., are you expecting the final result to necessarily be less than M? (more) |
— | 11 months ago |
| Comment | Post #288087 |
I don't think being akin to a statement in predicate logic is sufficient to make a question on topic for math. Contemplating the mortality of Socrates would also be off topic, unless it was specifically asking about applying modus ponens or something. Likewise, I think it would be okay if OP were usi... (more) |
— | almost 1 year ago |
| Comment | Post #288087 |
Not a math question. OP should perhaps ask this in a community for English language learners. (more) |
— | about 1 year ago |
| Comment | Post #287674 |
Arguably, this numeral system is better thought of as a mixed radix system alternating between bases 5 and 4 than as a simple base-20 system. There's a valid mathematical (or maybe mathematics-educational?) question about the pros and cons of mixed radix systems versus common radix systems (I think i... (more) |
— | over 1 year ago |
| Comment | Post #286961 |
There are probably plenty more functions that satisfy your conditions, but you should double-check exactly what your conditions are. $\sin(x)$ and its derivatives don't take values between 0 and 1 (they range from −1 to 1). (more) |
— | over 1 year ago |
| Comment | Post #286957 |
Not on my bookshelf, but I found an SE post that walks through the infinite-dimensional case. The result also appears [on Wikipedia](https://en.wikipedia.org/wiki/Dimension_(vector_space)#Properties), but uncited. More authoritative sources welcome. (more) |
— | over 1 year ago |
| Comment | Post #286130 |
Have you tried it to see what happens? (more) |
— | about 2 years ago |
| Comment | Post #285819 |
Doesn't $\varphi$ convex (and defined) everywhere imply that $\varphi$ is continuous, by a very standard result? (more) |
— | about 2 years ago |
| Comment | Post #285681 |
I'll edit my answer to include that information if you edit your question to incorporate my feedback (remove the irrelevant content related to Rothe-Hagen, including the incorrect assertion that Rothe-Hagen is a generalization of GVI) and include this more specific request.
I feel like I harp on t... (more) |
— | over 2 years ago |
| Comment | Post #285680 |
This is just a question about Vandermonde, not Rothe-Hagen; I suggest removing the Rothe-Hagen content.
(It's not the case that either of the two identities quoted are generalizations of each other; both are different ways to generalize the original Vandermonde identity. But this is a total aside ... (more) |
— | over 2 years ago |
| Comment | Post #285015 |
^ This. Honestly, actually following this advice on all of your intuition questions would improve most of them substantially.
But note that these are not examples of following this advice: ‘I don't understand.’ ‘How can this be?’ ‘This is sortilege!’
Instead:
* Connect the thing you're askin... (more) |
— | over 2 years ago |
| Comment | Post #284997 |
All the above is true even in the absurdly unlikely case (perhaps you don't realize just how idiosyncratic your writing style is) that you've reposted someone else's closed question verbatim. You still know it's a question that doesn't meet SE's standards, and so you've decided to try it out here ins... (more) |
— | over 2 years ago |
| Comment | Post #284997 |
I don't think you understand. This question isn't closed because it's a repost from SE. This question is closed because it's a bad question. It would be a bad question regardless of whether it was original or a repost. However, the fact that it's a repost of a closed question means that not only have... (more) |
— | over 2 years ago |
| Comment | Post #284996 |
I recommend editing your question to be that, if that's what it is. The thing about a minimal border around two points is still imprecise; if that's an important part of the question, explain a bit more, and otherwise remove it. (more) |
— | over 2 years ago |
| Comment | Post #284997 |
of calling for a proof-by-picture by linking to a question the premise of which is that proofs-by-picture are often misleading and that students should pay more attention to stuff like algebra. Hopefully this is you poking a little fun at yourself, and not... a less charitable interpretation. (more) |
— | over 2 years ago |
| Comment | Post #284997 |
This was closed Somewhere Else (https://math.stackexchange.com/questions/4314855/without-trial-and-error-averageaveragea-b-c-vs-averagea-averageb-c), and should be closed here for the same reason. You got good feedback on that post, ignored it, and submitted exactly the same question here without try... (more) |
— | over 2 years ago |
| Comment | Post #284996 |
I believe there's a lovely question in here somewhere but it hasn't emerged yet. Some questions for you: What do you mean by ‘dot’? Do you mean the same thing as ‘point’, or are you using a different word intentionally to signify something else? Is a ‘minimal border around ... two dots’ something oth... (more) |
— | over 2 years ago |
| Comment | Post #284723 |
Any expression that yields the result of addition seems like it would be pretty much just addition. But, for example, perhaps you'd be happy with something like $\ln{e^a e^b}$? If not, maybe you could be clearer about what you would and would not accept. (more) |
— | over 2 years ago |
| Comment | Post #284561 |
Your source might be using [Einstein notation](https://en.wikipedia.org/wiki/Einstein_summation), but there are other notations that give different meanings to upper and lower indices. I think you need to include more of the surrounding context to know for sure—a raised index doesn't universally mean... (more) |
— | over 2 years ago |
| Comment | Post #284551 |
Cheers, I added a paragraph that should clear that up. (more) |
— | over 2 years ago |
| Comment | Post #284051 |
There are many good questions about intuition and motivation, yes. I'm talking about a particular slim subset of those questions, where the next step in a proof is known, the reason that the step works is known, and the asker is only interested in, it would seem, the cognitive process that produced t... (more) |
— | over 2 years ago |
| Comment | Post #283900 |
@#53398, I agree that there are some ways that writing a proof is more like designing a bridge than writing a novel (and some ways that it is like neither). And yes, there are skeletons that get reused and are good to know. The sorts of questions I'm objecting to are not questions like, ‘What types o... (more) |
— | over 2 years ago |
| Comment | Post #283930 |
I'm not against (what I think is) the spirit of this answer, but I think it's out of place here. I'm not talking about questions where the asker doesn't know what the next step is; I'm talking about questions where the asker has been shown the next step, possibly understands how the step works, but w... (more) |
— | over 2 years ago |
| Comment | Post #283899 |
@DNB, I have given you specific feedback on each of these points on questions where they are applicable. At some point I stopped trying, since you didn't seem to be trying to incorporate the feedback into your future questions and I have better things to do with my time. But regardless, this question... (more) |
— | over 2 years ago |
| Comment | Post #283930 |
Is this an answer to the question? It seems mostly off-topic (although I might have made the question too distracting by mentioning some other problems that questions can have). (more) |
— | over 2 years ago |
| Comment | Post #283886 |
If you know both children are girls, then the information that the winter child is a girl is redundant; you know that it's a girl regardless of whether the event is described as ‘at least one winter girl’ or ‘at least one winter child’. (more) |
— | over 2 years ago |
| Comment | Post #283593 |
$f(x) = \frac{1}{x-1}$ is considered continuous. It's not defined at $x = 1$, so it has a disconnected domain, but it is continuous at all values where it is defined. (more) |
— | over 2 years ago |
| Comment | Post #283385 |
This is not a question about math. (more) |
— | over 2 years ago |
| Comment | Post #282615 |
Nope. As written, this is a complete answer to your original question. You asked a new question here in the comments. (more) |
— | almost 3 years ago |
| Comment | Post #282892 |
Have you tried to understand why? Take some example values of $s$, $c$, and $n$, and see what happens to the value of that fraction as $n$ increases. (more) |
— | almost 3 years ago |
| Comment | Post #282615 |
An algebraic expression is made exclusively of numbers, variables, and algebraic operations. $\ldots$ is none of these. This really isn't any more complicated than that. Doing algebra with informal notations can get you into trouble if you don't keep in mind what the informal notations mean. This is ... (more) |
— | almost 3 years ago |
| Comment | Post #282873 |
You moved your coloring back one paragraph. Look at the paragraph that is now above your red phrase. That is the explanation. And you need to explain why you think 2 and 3 are true; I can't read your mind. (more) |
— | almost 3 years ago |
| Comment | Post #282873 |
The answer to 1 was given just two paragraphs earlier. 2 and 3 are not true and not implied by anything in the solution. (more) |
— | almost 3 years ago |
| Comment | Post #282737 |
Is this a homework assignment? What have you tried? Where are you stuck? We can help but we aren't going to do the assignment for you. (more) |
— | almost 3 years ago |
| Comment | Post #282652 |
The variance argument is only relevant if you draw from the same urn multiple times, which isn't part of the original problem. With one draw, the author is correct that you should be indifferent. Your argument is interesting additional information, but I think it's misleading to present it as a count... (more) |
— | almost 3 years ago |
| Comment | Post #282615 |
$\ldots$ doesn't work like that; you can't simply substitute a variable into that kind of informal, descriptive expression without thinking about what the notation as a whole represents. It's not an algebraic expression, so the rules of algebra don't apply. $\ldots$ is a signal to look at the pattern... (more) |
— | almost 3 years ago |
| Comment | Post #282623 |
I think the feedback given in the other thread is better. Citing edition and page number doesn't make the question any clearer; it just makes it possible for someone to do detective work to fill in details that the asker should have provided in the first place. An image of the page doesn't lead to a ... (more) |
— | almost 3 years ago |
| Comment | Post #282622 |
Related: https://math.codidact.com/posts/280856#answer-280857 (more) |
— | almost 3 years ago |
| Comment | Post #282616 |
An understandable mistake, but one you perhaps could have caught yourself if you had thought about your own interpretation a little more. $k$ doesn't make sense as the number of ways to choose $k$ team members, any more than $\(^n_k\)$ makes sense as the number of ways to choose one of them to be cap... (more) |
— | almost 3 years ago |
| Comment | Post #282611 |
We've had words before about the appropriateness of screenshots in questions. In this case, the quoted text doesn't seem to be relevant to your question. The question is about the screenshotted text, which is completely different, and from an online source which I seem to be able to copy from just fi... (more) |
— | almost 3 years ago |
| Comment | Post #282615 |
I don't even know what the middle expression in that line is supposed to mean. You start at $n$, and then descend to $n - 1$, and by the end somehow... wrap around to $n + 2$, $n + 1$? What's happening in between, where the ellipsis is? How did you arrive at that as what $LHS\|_{k=1}$ should represen... (more) |
— | almost 3 years ago |
| Comment | Post #282611 |
You screenshotted a website? Is this an elaborate troll or something? (more) |
— | almost 3 years ago |