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https://math.stackexchange.com/questions/153902/un-countable-union-of-open-sets
Jun 4, 2012 · A remark: regardless of whether it is true that an infinite union or intersection of open sets is open, when you have a property that holds for every finite collecti
https://math.stackexchange.com/questions/1525176/where-can-i-find-the-paper-un-th%C3%A9or%C3%A8me-de-compacit%C3%A9-by-j-p-aubin
Nov 12, 2015 · J. P. Aubin, Un théorème de compacité, C.R. Acad. Sc. Paris, 256 (1963), pp. 5042–5044. It seems this paper is the origin of the "famous" Aubin–Lions lemma.
https://math.stackexchange.com/questions/2207334/como-calcular-el-area-de-la-superficie-de-un-huevo-con-calculo?noredirect=1&lq=1
Estoy haciendo mi reciente evaluación interna del IB Matemáticas HL y mi tema es cómo calcular el área de superficie de un huevo . Quiero aplicar el cálculo conocimiento en es
https://math.stackexchange.com/questions/2067272/limit-sequence-un-and-vn
Limit sequence (Un) and (Vn) Ask Question Asked 9 years, 3 months ago Modified 9 years, 3 months ago
https://math.stackexchange.com/questions/314846/for-what-n-is-u-n-cyclic
When can we say a multiplicative group of integers modulo $n$, i.e., $U_n$ is cyclic? $$U_n=\\{a \\in\\mathbb Z_n \\mid \\gcd(a,n)=1 \\}$$ I searched the internet but ...
https://math.stackexchange.com/questions/1600525/intuitive-proof-that-un-isnt-isomorphic-to-sun-times-s1
Jan 5, 2016 · The "larger" was because there are multiple obvious copies of $U (n)$ in $SU (n) \times S^1$. I haven't been able to get anywhere with that intuition though, so it .
https://math.stackexchange.com/questions/2993418/mnemonic-for-integration-by-parts-formula
Nov 11, 2018 · The Integration by Parts formula may be stated as: $$\\int uv' = uv - \\int u'v.$$ I wonder if anyone has a clever mnemonic for the above formula. What I often do i
https://math.stackexchange.com/questions/3164783/prove-that-the-sequence-11-nn-is-convergent
Mar 27, 2019 · I know the proof using binomial expansion and then by monotone convergence theorem. But i want to collect some other proofs without using the binomial expansion. *i