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3 questions
6
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4
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roots of higher derivatives of exponential
Consider the Gaussian function $f(z)=e^{-z^2}$ which has no zeros on the complex domain. Let $D$ denote derivative w.r.t. the variable $z$.
Question. Is it true that $D^nf(z)=0$ has only real roots ...
4
votes
2
answers
443
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Largest absolute value of a polynomial of degree $n$ on $\{0,1,\ldots,n\}$
Consider a polynomial $P_n(x)\in\mathbb{R}[x]$, of degree $n\geq1$, of the form
$$P_n(x)=c_0+c_1x+c_2x^2+\cdots+c_{n-1}x^{n-1}+x^n.$$
To illustrate the question, take $P_1(x)=c_0+x$ so that $P_1(0)=...
4
votes
2
answers
334
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what is this sum of squares of algebraic functions?
This question is inspired by the MO query here, although it has no direct implications.
Define the family of polynomial functions
$$f_n(x)=n^2x^{n-1}-\frac{d}{dx}\left(\frac{x^n-1}{x-1}\right),$$
and ...