2,282 reputation
1728
bio website
location
age
visits member for 1 year, 11 months
seen Aug 20 at 9:35

Apr
23
comment Be $G=\{ e,g_1,g_2,\ldots, g_n \}$, $|G|=n+1$. Suppose $G$ has a unique element of order $2$, say $g_1$. Show that $eg_1g_2\ldots g_n=g_1$.
@marcelolpjunior You mean you proved it for $n$ odd, then discarded the case of $n$ even because $n$ is never even? If so, that's correct.
Apr
23
revised Different methods of calculating $\zeta(s)$'s Laurent series.
edited title
Apr
23
comment Different methods of calculating $\zeta(s)$'s Laurent series.
@robjohn Would it be too radical a change to change the question to 'ways to calculate the Laurent series of zeta', or is it better to delete and reask?
Apr
23
answered Be $G=\{ e,g_1,g_2,\ldots, g_n \}$, $|G|=n+1$. Suppose $G$ has a unique element of order $2$, say $g_1$. Show that $eg_1g_2\ldots g_n=g_1$.
Apr
23
asked Different methods of calculating $\zeta(s)$'s Laurent series.
Apr
22
reviewed Approve suggested edit on Interior of the set {1/n}
Apr
22
comment Convergence of $\sum_{n=3}^{\infty}\frac{1}{n\log n(\log\log n)^\alpha} $
@GinKin $u=\log\log x, du= \frac{dx}{x \log x}$.
Apr
22
reviewed Approve suggested edit on Logarithmic problem with 2 variables help
Apr
20
comment Integral$=-\frac{4}{3}\log^3 2-\frac{\pi^2}{3}\log 2+\frac{5}{2}\zeta(3)$
@Integrals The main question involves two equalities. Are you unsure about how to prove both or only the last?
Apr
20
reviewed Approve suggested edit on Good Textbooks for Real Analysis and Topology.
Apr
20
comment About a harmonic series problem : How to prove that $\sum_{n=1}^{\infty}\frac{H_n}{n^3}=\frac{\pi^4}{72}$
The final link is dead now.
Apr
20
comment Compute $\int_0^\infty \frac{\ln x}{(1+x)^3}\,\mathrm{d}x$
Do you know differentiating under the integral?
Apr
20
reviewed Approve suggested edit on A fascinating number chain.
Apr
20
reviewed Approve suggested edit on A problem on mathematical induction
Apr
18
reviewed Approve suggested edit on Does a solution to the differential equation $y'=y$ exist?
Apr
18
reviewed Approve suggested edit on show a set is lebesgue measurable
Apr
18
awarded  Custodian
Apr
18
reviewed Approve suggested edit on poincare-bendixson theorem contradiction
Apr
18
answered Solid of revolution vs $\iiint$
Apr
18
comment How to find $\nabla$ in spherical coordinates
I'd have thought that $x=r\sin \theta \cos\phi, y= r \sin \theta \sin \phi, z=r \cos \theta$ and the chain rule for partial derivatives is enough (though messy).