Homotopy groups U(N) and SU(N): $\\pi_m(U(N))=\\pi_m(SU(N))$
2017年10月3日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Calculate the cohomology group of $U(n)$ by spectral sequence.
2015年5月31日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Equation of a rectangle - Mathematics Stack Exchange
2011年10月2日 · For purposes of plotting with a computer, the implicit equation isn't terribly convenient to handle, so I'll throw in a set of parametric Cartesian equations for free, based on the parametric equations of the Lamé curve:
Expectation of Minimum of $n$ i.i.d. uniform random variables.
2017年4月25日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
$\\operatorname{Aut}(\\mathbb Z_n)$ is isomorphic to $U_n$.
2023年8月3日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
math history - Why do the French count so strangely?
2013年5月15日 · Similarly, 80 is also not invented, it is 4 20s, quatre-vingt. 81 is 4 20s 1, quatre-vingt-un. 90 is, 4 20s 10, quatre-vingt-dix. 91 is 4 20s 11, quatre-vignt-onze. Finally, they have a word for 100, ceut. It looks similar to roman numbers Roman number system, where you repeat the letters to combine the values. X is 10 XX is 20 and so on.
Calculating the Order of An Element in A Group
A group can have finite or infinite number of elements. When the group has finite number of elements, we see the least POSITIVE n i.e.(n>0) such that g^n gives the identity of the group (in case of multiplication) or n*g gives the identity (in case of addition).
I have learned that 1/0 is infinity, why isn't it minus infinity?
$\begingroup$ @Swivel But 0 does equal -0. Even under IEEE-754. The only reason IEEE-754 makes a distinction between +0 and -0 at all is because of underflow, and for +/- ∞, overflow.
Find the sum of the series $\\sum \\frac{1}{n(n+1)(n+2)}$
2015年3月26日 · 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.
Infinite series $\\sum _{n=2}^{\\infty } \\frac{1}{n \\log (n)}$
Here is another possible answer. We will derive the asymptotic formula of the partial sum $\sum_{1< n\leqslant x}\frac{1}{n\log n}$ to show that this series diverges.