Christian Ivicevic
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 May 13 awarded Caucus Apr 9 comment Infinite sets don't exist!? You could mention, that Von Neumann proposed that all natural numbers can be bootstrapped out of the empty set by the operation you described. Mar 28 awarded Popular Question Mar 28 awarded Popular Question Mar 4 awarded Popular Question Feb 18 answered $E^2[X]$ vs.$E[X^2]$, what's the difference? Jan 27 awarded Tumbleweed Jan 20 asked Properties of shortest walks and simple paths during optimization Jan 20 accepted Parameterized curve describing trajectory of thrown object Jan 16 comment When is $f(x) = \frac{ax}{e^{-b}-{(e^{c})}^x}$ monotonic? By the way, is this a homework related question? If so, then please consider adding the appropriate tag - furthermore show what you have done so far and what you don't understand so we see that you at least tried something. Jan 16 answered When is $f(x) = \frac{ax}{e^{-b}-{(e^{c})}^x}$ monotonic? Jan 14 comment Parameterized curve describing trajectory of thrown object I don't know whether this is correct, but we never did such complicated computations in class. I tried to solve this problem now by not factorizing so that I have $\sqrt{v_0^2\cos^2\beta+(v_0\sin\beta-gt)^2}$ and simplify that with other (much easier) approaches. Do you have some other suggestions? Jan 14 comment Parameterized curve describing trajectory of thrown object Actually I never saw this method, but I think that this yields $\int \|k'(u)\|\,\mathrm du=\frac{1}{2}g\left(u-\frac{v_0\sin(\beta)}{g}\right)^2+v_0\cos(\beta)u+\text{c‌​onstant}$. Did I understand this substitution right? Jan 14 asked Parameterized curve describing trajectory of thrown object Jan 8 comment Proving that $\left(\frac{1}{0!}+\frac{1}{1!}+\frac{1}{2!}+\frac{1}{3!}+\cdots+\frac{1}{n!}\right)$ has a limit Careful, you say that $x_n$ is a finite sum and saying that it equals an infinite sum. Furthermore you ambiguously use $n$. These are just small mistakes with the notation. How about saying $\lim_{n\to \infty} x_n = \lim_{n\to \infty} \frac{1}{0!}+\ldots+\frac{1}{n!}=\sum_{k=0}^{\infty}\frac{1}{k!}=e$? Jan 7 comment If $\sum_{n=1}^\infty a_n$ is convergent, then $\sum_{n=1}^{\infty} a_n\sin(n)$ @GEdgar: I thought about that fact that $|\sin(n)|\leq 1$ like Andrew mentioned this could be an "easier" example to simplify $\sin$ if you understand. Jan 7 revised If $\sum_{n=1}^\infty a_n$ is convergent, then $\sum_{n=1}^{\infty} a_n\sin(n)$ edited body Jan 7 answered If $\sum_{n=1}^\infty a_n$ is convergent, then $\sum_{n=1}^{\infty} a_n\sin(n)$ Jan 7 comment If $\sum_{n=1}^\infty a_n$ is convergent, then $\sum_{n=1}^{\infty} a_n\sin(n)$ Have you tried to think about $(-1)^n\cdot\frac{1}{n}\to 0$? This could be some motivation. Jan 7 revised Differentiation with respect to integral boundary Had some horrible mistakes in the example - these are fixed now.