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For what $n$ is $U_n$ cyclic? - Mathematics Stack Exchange
17 Un U n is cyclic iff n n is 2 2, 4 4, pk p k, or 2pk 2 p k, where p p is an odd prime. The proof follows from the Chinese Remainder Theorem for rings and the fact that Cm ×Cn C m × C n is …
Mnemonic for Integration by Parts formula? - Mathematics Stack …
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 is to derive it …
Calculate the cohomology group of $U(n)$ by spectral sequence.
May 31, 2015 · Here U(n) is the unitary group, consisting of all matrix A ∈ Mn(C) such that AA ∗ = I Problem How to calculate the integer cohomology group H ∗ (U(n)) of U(n)? What if O(n) …
Find the sum of the series $\\sum \\frac{1}{n(n+1)(n+2)}$
Mar 26, 2015 · I got this question in my maths paper Test the condition for convergence of $$\sum_ {n=1}^\infty \frac {1} {n (n+1) (n+2)}$$ and find the sum if it exists. I managed to show …
Expectation of Minimum of $n$ i.i.d. uniform random variables.
Apr 25, 2017 · To calculate the expected value, we're going to need the density function for Y Y. To get that, we're going to need the distribution function for Y Y. Let's start there. By definition, …
How can I find a mod with negative number? [duplicate]
I know how to solve mod using division i.e. $$11 \\mod 7 = 4$$ For this I did a simple division and took its remainder: i.e. $$11 = 7 \\cdot 1 + 4$$ Where $11$ was dividend, $7$ divisor, $1$ …
What does $QAQ^{-1}$ actually mean? - Mathematics Stack …
Apr 28, 2020 · I'm self-learning Linear Algebra and have been trying to take a geometric approach to understand what matrices mean visually. I've noticed this matrix product pop up repeatedly …
When is the group of units in $\\mathbb{Z}_n$ cyclic?
Let Un U n denote the group of units in Zn Z n with multiplication modulo n n. It is easy to show that this is a group. My question is how to characterize the n n for which it is cyclic. Since the …
Difference between "≈", "≃", and "≅" - Mathematics Stack Exchange
In mathematical notation, what are the usage differences between the various approximately-equal signs "≈", "≃", and "≅"? The Unicode standard lists all of them inside the Mathematical …