Reputation
7,059
Next privilege 10,000 Rep.
Access moderator tools
Badges
1 14 37
Impact
~172k people reached

13h
comment Cardinality of equivalence relations on N
I just interpreted it as "I'd like to show how many ways we can partition $\mathbb{N}$, is it at least $2^{\aleph_0}$?". It feels similar in flavor to his other question.
13h
answered Cardinality of equivalence relations on N
13h
reviewed Looks OK How can we show that $ \sum_{n=0}^{\infty}\frac{2^nn[n(\pi^3+1)+\pi^2](n^2+n-1)}{(2n+1)(2n+3){2n \choose n}}=1+\pi+\pi^2+\pi^3+\pi^4 ?$
13h
reviewed Close improper integral of exponential function that contains a square root
13h
reviewed Leave Open Lagrangian method with objective function and constraints in expected value form.
13h
reviewed Leave Open abstract algebra: finite fields and galois group
13h
reviewed Close Ellipticity of an operator
13h
reviewed Leave Open Prove that for every sufficiently large n, exists a k-paradoxical tournament on n vertices
13h
reviewed Leave Open Galois extension of degree $2^n$
13h
comment What is the binary operations in $\mathbb{D}(n)$
The only way I can interpret "algebraic definition" is group presentation. Perhaps I should be more clear that the presentation is the point of the answer.
13h
reviewed Close Length of the side of a regular pentagon is $a$ & length of diagonal is $b$. Value of $\frac{a^2}{b^2}+ \frac{b^2}{a^2}=$?
13h
reviewed Leave Open Limit Point and Sequences Theorem
13h
reviewed Close about Lebesgue integral functions
13h
reviewed Leave Open if p and q are distinct primes and n=p q then there is a primitive root mod n
13h
reviewed Leave Open Can you recommend a book about multivariable mathematical analysis?
13h
comment Transform the equation into homogeneous equation and then solve
What have you tried?
13h
answered What is the binary operations in $\mathbb{D}(n)$
May
1
comment If a function maps an input to its inverse, is it bijective?
What is $X$? If it's a group, then $x^{-1}$ makes sense. But if it's a topological space, what would $x^{-1}$ mean?
Apr
28
comment Prove that if Aut($G$) is the trivial group, then so is $G$?
Hint: for abelian groups, the map $g \mapsto g^{-1}$ is an automorphism.
Apr
14
revised Solve without using quadratic formula: $\frac{4}{3x+3} = \frac{12}{x^2 - 1}$.
added 207 characters in body