Dennis Gulko
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13,040
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 17 If $f\circ g$ is continuous and $g$ is continuous what about $f$? 16 $2\times2$ matrices are not big enough 16 Calculate:$\displaystyle \int 5^{x+1}e^{2x-1}dx$ 15 Divisibility of 9 and $(n-1)^3 + n^3 + (n+1)^3$ 13 If $|\lbrace g \in G: \pi (g)=g^{-1} \rbrace|>\frac{3|G|}{4}$, then $G$ is an abelian group.

### Reputation (13,040)

 +10 Find the value of : $\lim_{x\to\infty} \sqrt{x+\sqrt{x}}-\sqrt{x}$ +20 $2\times2$ matrices are not big enough +10 number of combinations without repetition with limited supply +10 Automorphism groups and symmetric groups

### Questions (13)

 12 Does the Zariski closure of a maximal subgroup remain maximal? 8 Degeneracy of outerplanar graphs 5 Origin of a problem in graph theory/planar geometry 4 Exercise from Serre's “Trees” - prove that a given group is trivial 4 Closed form of $\sum_{k=0}^nk\binom{k}{3}\binom{2n}{k}$

### Tags (139)

 162 linear-algebra × 74 80 complex-analysis × 33 107 group-theory × 31 71 algebra-precalculus × 29 100 calculus × 44 65 combinatorics × 28 88 abstract-algebra × 25 64 integration × 18 86 matrices × 29 47 real-analysis × 14

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 Mathematics 13,040 rep 12249 MathOverflow 155 rep 17 Stack Overflow 101 rep 2 TeX - LaTeX 101 rep 1 Mathematica 101 rep 1