- (Un-)Countable union of open sets - Mathematics Stack Exchange
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 collection of sets (in this case, the union or intersection of any finite collection of open sets is open) the validity of the property for an infinite collection doesn't follow from that In other words, induction helps you prove a
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- Mnemonic for Integration by Parts formula? - Mathematics Stack Exchange
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 is to derive it from the Product R
- The sequence of integers - Mathematics Stack Exchange
Prove that the sequence $\\{1, 11, 111, 1111, \\ldots\\}$ will contain two numbers whose difference is a multiple of $2017$ I have been computing some of the immediate multiples of $2017$ to see how
- Prove that the sequence (1+1 n)^n is convergent [duplicate]
It is hard to avoid "the concept of calculus" since limits and convergent sequences are a part of that concept On the other hand, it would help to specify what tools you're happy with using, since this result is used in developing some of them (For example, if you define ex = limn→∞(1 + x n)n e x = lim n → ∞ (1 + x n) n, then clearly we should not be using ex e x in the process of
- probability - If $U\sim U (-1,1)$ and $N\sim N (0,1)$ are independent . . .
If X2 X 2 is not constant, then we cannot have independence between X X and XN X N In particular, if U U follows a uniform law on [−1, 1] [1, 1] (or any interval), the random variables U U and UN U N are not independent
- functional analysis - Where can I find the paper Un théorème de . . .
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 This lemma is proved, for example, here and here, but I'd like to read the original work of Aubin However, all I got is only a brief review (from MathSciNet)
- Divergence of series sin (1 n) - Mathematics Stack Exchange
Since − 1 ≤ sin(1 n) ≤ 1 and limn → ∞ − 1 ≠ limn → ∞1 can I use the nth-term test to prove that the series will diverge? I've only seen the problem done using the limit comparison test and am not sure if I can use the nth-term test
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