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Don't have much time these days...


Sep
10
comment stopping time and martingale
@Vaolter: If you do not edit the question to 1) Make the title more meaningful 2) Make the question make some sense, the question might get closed soon. Also, with that sarcastic attitude you will only cause people to ignore you.
Sep
10
comment We can divide $7^{17} - 7^{15}$ by?
@BBischof: If you are talking about homework, I actually agree with you (of not just handing the solution on a platter). If you are talking about answers way beyond the asker's capabilities (like Bill's) then I don't see why there should be no conversations. Anyway, I will stop now.
Sep
10
comment We can divide $7^{17} - 7^{15}$ by?
@J.M: It happens. The upvotes are an indication of how the community understands/likes your answer, nothing to do about the difficulty/brilliance/quality of the answer. Perhaps this might be of interest to you: meta.stackexchange.com/questions/31253/…
Sep
10
comment Orthant probability / passage-time
All the questions you have asked so far seem to be from the same subject. Is this homework?
Sep
10
awarded  Enthusiast
Sep
9
comment We can divide $7^{17} - 7^{15}$ by?
@BBischof: The point of stack exchange sites is to give answers, not hints. If you think it is homework, clarify it before answering. Given the fact that OP even has this question (thus indicating a mathematics newbie), talking about various weirdly named polynomial identities, is very likely irrelevant to the OP, even as a well phrased hint. Of course, Bill's answer would definitely help others who happen to come across this question. On the other hand, those who can understand Bill's answer probably don't need any help on this question.
Sep
9
comment Can non-linear transformations be represented as Transformation Matrices?
I tried to convert to the 2D matrix. You need to use ` \\\\ ` (four of them instead of two). Also, I added a couple of \det which I presume were missing.
Sep
9
revised Can non-linear transformations be represented as Transformation Matrices?
matrix.
Sep
9
revised Generalizing $\sum \limits_{n=1}^{\infty }n^{2}/x^{n}$ to $\sum \limits_{n=1}^{\infty }n^{p}/x^{n}$
fix up table.
Sep
9
revised Generalizing $\sum \limits_{n=1}^{\infty }n^{2}/x^{n}$ to $\sum \limits_{n=1}^{\infty }n^{p}/x^{n}$
added 360 characters in body; added 21 characters in body
Sep
9
answered Generalizing $\sum \limits_{n=1}^{\infty }n^{2}/x^{n}$ to $\sum \limits_{n=1}^{\infty }n^{p}/x^{n}$
Sep
9
awarded  Nice Answer
Sep
9
comment Big O boundary condition truth value
@Sev: Yeah, unfortunately there could be different definitions of BigOh out there!
Sep
9
awarded  Nice Question
Sep
8
comment Finding the least positive integer such that $\sum \cos{\theta_{i}} \leq \gamma$
I am not sure if this is right. For $i = 1 \dots n-1$ pick $\theta_{i}$ such that $\cos \theta_{i} > 1 - 1/n$. Pick $\theta_{n}$ so that the constraint is satisfied. We also have $\cos \theta_{n} > 0$. For these $\theta_{i}$, $\sum \cos \theta_{i}$ is at least $n-2$
Sep
8
comment Big O boundary condition truth value
@Sev: n*sin(npi/2) can be one of three, 0, n or -n. So you can't ignore that. Choosing C=3 actually proves that the statement is true. Remember, we have been talking about BigOh all the while, where 2n is same as 1000000n (i.e. constants don't matter). That is one of the reasons why the base of the logarithm is irrelevant too.
Sep
8
comment How to derive the number of pairwise combinations of a set of factors?
Not sure what you are asking. Maybe an example to make it clearer?
Sep
8
revised We can divide $7^{17} - 7^{15}$ by?
tex
Sep
8
comment Is this a known algebraic identity?
@Bryon: True, but proving it just for numbers in (0,1) is enough, as we can get a polynomial identity in any variable we want and that would generalize to complex numbers.
Sep
8
comment Is this a known algebraic identity?
@Byron: If you have a solution and are looking for a different proof, I suggest you mention your approach in the question itself. This will save everyone some time.