### Questions (89)

 22 Geometrical interpretation of $(\sum_{k=1}^n k)^2=\sum_{k=1}^n k^3$ 11 For which $n$ is $\mathbb{A}^n\setminus \{0\}$ an affine variety? 9 Non-Abelian group $G$ in which $x\mapsto x^3$ is a homomorphism 7 What does it mean to be functorial (in something)? 7 What is $\limsup_{n\to\infty} \frac{p_{n+1}}{p_n}$?

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 8 If $[a,b]$ is an interval of minimal length with $\int_a^bf(x)dx=\alpha$ then $f(a)=f(b)$ 6 Show that $x^2+x+4$ is irreducible over $\mathbb Z_{11}$. 6 If $f$ and $g$ are continuous on $\Bbb R$ and $f\left(\frac{p}{q}\right)=g\left(\frac{p}{q}\right)$ then is it true that $f(x)=g(x)$? 5 If the derivative tends to $0$ at infinity, does the function have a limit? 5 Find the determinant of $A + I$

### Tags (144)

 37 real-analysis × 19 12 functions × 5 21 linear-algebra × 15 11 general-topology × 15 18 matrices × 6 9 sequences-and-series × 9 16 abstract-algebra × 15 9 improper-integrals × 2 14 irreducible-polynomials × 4 8 limits × 4

### Bookmarks (46)

 189 Good books and lecture notes about category theory. 42 Yoneda-Lemma as generalization of Cayley`s theorem? 37 $\mathbb{A}^{2}$ not isomorphic to affine space minus the origin 34 Show that a proper continuous map from $X$ to locally compact $Y$ is closed 33 necessary and sufficient condition for trivial kernel of a matrix over a commutative ring