Hagen von Eitzen
Reputation
97/100 score
 May 5 reviewed Close Quadrilateral $APBQ$. May 5 reviewed Looks OK Why is something not a field if it's a proper class? May 5 comment For which $z \in \Bbb{C}$ does this series converge? @iwriteonbananas The proof becomes simpler by observing the symmetry of the expression. May 5 revised For which $z \in \Bbb{C}$ does this series converge? added 174 characters in body May 5 comment Can this relation be transitive but not symmetric and reflexive? How about $<$ on $\{1,2,3\}$? May 5 answered Why do Z/7 have no cubic root of 2? May 5 reviewed No Action Needed Find the original value without VAT May 5 comment Odd or even function? @user134785 So at least one of you two has a wrong answer. But yours is fine May 5 answered For which $z \in \Bbb{C}$ does this series converge? May 5 comment Zeroes of a complex function The more interesing part is why zero Taylor series imlpies zero in a naighbourhood. You may want to add that your functions should be anylatic or such May 5 answered $f: \mathbb R \rightarrow \mathbb R, f(x+y)=f(x)+f(y), \forall x,y \in \mathbb R$. If $lim_{x \rightarrow 0} f=L$, prove that $L=0$ May 5 comment Positivity of power function. @MuhammadCamran It appears that this is your most recent question ... May 5 reviewed Looks OK Parametrising a Sphere May 5 revised Union of connected sets added 723 characters in body May 5 answered Union of connected sets May 5 answered Does extreme value theorem hold for neighborhoods near $\pm \infty$ May 5 answered Something screwy going on in $\mathbb Z[\sqrt{51}]$ May 4 answered continuity and differentiable equivalent to 0 May 4 comment continuity and differentiable equivalent to 0 MVT is certainly a good idea. But the rest is ... not so compelling. Especially, "Therefore $0\le f'(x)\le 2 f(x)$" makes little sense when that is in fact a given property of $f$ May 4 comment What matrix transforms $(1, 0)$ into $(2, 6)$ and tranforms $(0, 1)$ into $(4, 8)$? +1 for the closing line