Ewan Delanoy
Reputation
31,968
89/100 score
4 24 78
Impact
~176k people reached

 22 Does there exist rational $a,b,c$, such that $\sqrt[3]{1}+\sqrt[3]{2}+\sqrt[3]{4}=\sqrt[3]{a}+\sqrt[3]{b}+\sqrt[3]{c}$ 19 Let $a_{i} \in\mathbb{R}$ ($i=1,2,\dots,n$), and $f(x)=\sum_{i=0}^{n}a_{i}x^i$ such that if $|x|\leqslant 1$, then $|f(x)|\leqslant 1$. Prove that: 16 Example of two dependent random variables that satisfy $E[f(X)f(Y)]=Ef(X)Ef(Y)$ for every $f$ 12 How to represent Fermat number $F_n$ as a sum of three squares? 12 what is the sum of this?$\frac12+ \frac13+\frac14+\frac15+\frac16 +\dots\frac{1}{2012}+\frac{1}{2013}$

### Reputation (31,968)

 +35 prove that $x^{2\cdot 3^n}+x^{3^n}+1$ is not primitive (mod 2) +10 A matrix w/integer eigenvalues and trigonometric identity +10 if $x+y+z=2$ and $xy+yz+zx=1$,Prove $x,y,z \in \left [0,\frac{4}{3} \right ]$ +5 How many generators needed for Pell-equation-related group

### Questions (240)

 28 A circle in the plane contains at most four lattice points? 27 Smallest order for finite group that needs many elements to generate it 15 Why is $(\sqrt{2}+\sqrt{3})^{2008}$ so close to an integer? 15 Every endomorphims is a linear combination of how many idempotents in infinite dimensions? 15 Comparing countable models of ZFC

### Tags (236)

 219 linear-algebra × 113 127 algebra-precalculus × 31 183 inequality × 74 106 number-theory × 42 156 real-analysis × 108 102 matrices × 49 154 polynomials × 112 89 calculus × 32 144 abstract-algebra × 61 77 analysis × 24

### Accounts (18)

 Mathematics 31,968 rep 42478 Stack Overflow 533 rep 412 TeX - LaTeX 341 rep 16 MathOverflow 336 rep 27 English Language & Usage 163 rep 4