MyUserIsThis
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 Feb4 answered Question about infinity sum Feb4 comment Question about infinity sum @GerryMyerson Yes, I just saw it, thanks. Feb4 asked Question about infinity sum Feb1 comment Prove that for $a > 0$, $\lim_{n \rightarrow \infty}{\frac{a^n}{n!}=0}$ The proof is correct but, as @DavidMitra says, you're using a sledgehammer :) So I don't find it very clean, you should be able to prove then that those series are equal to $e^x$ and that they converge, using taylor's theorem also does the trick but it's more advanced that the analysis corresponding to this. Final message: I would look for another proof, but if I saw this in an exam and nothing came to my mind, I would undoubtedly use yours and it would be correct. Jan30 answered Finding limit of the sequence $A_n = \frac{n^3 + n!}{2^n + 3^n}$ Jan27 comment Group relations and generators @ThomasAndrews I wrote my work, is anything wrong? Jan27 revised Group relations and generators added 215 characters in body Jan26 comment Group relations and generators @anon yes, that was a typo. I wrote what I've done. Jan26 revised Group relations and generators added 338 characters in body Jan26 revised Group relations and generators added 8 characters in body Jan26 comment Group relations and generators Yes it's abelian. I got the twelve just by transforming the relations and getting new generators, until I had something of the form $zu_1=0$ So I know that corresponds to $Z/xZ$ Jan26 asked Group relations and generators Jan25 comment What kind of logic is mine? BTW, if you want a very divulgative and great book about mathematical logic, you might like GEB, by Douglas Hofstadter Jan25 comment What kind of logic is mine? I guess a theory is a set of axioms and rules of inference that allow you to somehow relate those axioms. That $P$ is provable under $T$ means that from those axioms and with those rules, you can build $P$ as a theorem. For example, under the Peano axioms, defining the sum $m+n$ recursively to get to the axiom os succesors, $P:3+2=5$ is provable. The rules could be that if $m+n=a$ is an axiom or a theorem, then $s(m)+n=s(a)$ and $m+s(n)=s(a)$ are also theorems, with $s(m)$ referring to the succesor of a natural number as defined by those Peano axioms. Jan20 answered Integrate $\frac{\mathrm d x}{\sqrt{2x+1}}$ from 0 to 4 Jan19 revised Differential equation $uu''-u'^2=u'$ edited body Jan19 comment Differential equation $uu''-u'^2=u'$ @did Yes, that was a typo, it was fine in my paper. Thanks. Jan19 accepted Differential equation $uu''-u'^2=u'$ Jan19 comment Differential equation $uu''-u'^2=u'$ God I feel so stupid Jan19 revised Differential equation $uu''-u'^2=u'$ added 264 characters in body