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Jan
16
revised About this limit, $\lim_{t\to0^+} \sum_{n=1}^\infty \frac{\sqrt t}{1 + tn^2}$
more informative title
Jan
16
revised Evaluating a limit, $\lim_{t\rightarrow 0^{+}} {\sum_{n=1} ^{\infty} \frac{\sqrt{t}}{1+tn^2}}$
more informative title
Jan
16
revised How to find the limit of a sum of reciprocals $\lim_{n\to\infty}(1 + \frac{1}{2} + \frac{1}{3} + \cdots+ \frac{1}{n})$?
more informative title
Jan
15
comment Binomial coefficient (mod m)
If it's a programming question, you should post it to the programming website, not here.
Jan
15
comment Difference between an injective f and monotonic f?
Think about discontinuous functions.
Jan
15
comment Looking for a general and complete solution to the Diophantine $a^2 -2b^4 = -1$
Now here's where aesthetics becomes mathematics. You write, b^2n. How is one to know whether you mean $b^{2n}$ or $b^2n$? If you plan to use this site regularly, please do yourself and others a favor, and learn a little about how to use TeX to format your mathematics here.
Jan
15
revised Calculating wholesale and shipping costs for book order
edited tags, more informative title
Jan
15
comment Stable method to compute $A^n$ for this defective matrix $A$?
Singularity has nothing to do with eigendecomposition. Singularity means zero is an eigenvalue. $A$ is diagonalizable if and only if it has 12 linearly independent eigenvectors. These two properties are independent of each other --- knowing a matrix does or doesn't have one property does not tell you whether or not it has the other.
Jan
15
revised integer transform
added 494 characters in body
Jan
15
answered Looking for a general and complete solution to the Diophantine $a^2 -2b^4 = -1$
Jan
15
comment Looking for a general and complete solution to the Diophantine $a^2 -2b^4 = -1$
I have no idea what you are talking about. I repeat: if you have a problem with the editing that Elias and I did, flag your question for moderator attention.
Jan
15
comment Find two short exact sequences of abelian groups such that two of them are isomorphic, however the third is not
Let $A$ be generated by $a$ and $b$ subject to $a^2=1$, $b^4=1$, $ab=ba$, and let $B'$ be the subgroup generated by $b^2$.
Jan
12
comment Looking for a general and complete solution to the Diophantine $a^2 -2b^4 = -1$
If you have a problem with editing, flag it for moderator attention. But I think you will find that editing for aesthetics and spelling is considered a good thing here.
Jan
12
answered Find two short exact sequences of abelian groups such that two of them are isomorphic, however the third is not
Jan
12
comment How do you express $f(x)$ given the following inequalities
You have written $0\lt x\le50=0$, which is clearly not what you meant to write, since $50$ doesn't equal zero. Can you edit the body of your question, please, to bring it into line with what you actually mean to ask?
Jan
12
comment Find two short exact sequences of abelian groups such that two of them are isomorphic, however the third is not
"such that two of them are isomorphic" --- such that two of what are isomorphic?
Jan
12
comment Algebraic Number Theory - Integral Basis
@YACP, on this site, where peoploe regularly ask for $2+2$, no question about an integral basis for the ring of integers in an algebraic number field is trivial.
Jan
12
comment Problem about BCH code
Suggestions: look up the definition of BCH code: look up the definition of dual of a code: look at some other examples where there are proofs that one code is the dual of another.
Jan
12
answered integer transform
Jan
12
comment integer transform
If $x$ is in $X$ then $(x,y)$ isn't in $X$, it's in $X\times X$. Can you edit your question so it reflects what you actually mean, please?