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Mathematics
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Feng's user avatar
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Feng
  • Member for 6 years
  • Last seen more than a month ago
  • China
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How to study math?

Don't just read it; fight it!

-------Paul Halmos

An interesting figure

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Requests for Reopen & Undeletion Votes (volume 01/2022 - today)
Jul 7, 2022
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24
compute $\int_0^1\sqrt{x(1-x)}dx$.
22
How to show analytically that $x^4-4x^3-2x^2+16x+24=0$ has no solutions in $\mathbb{R}$?
19
Let $ f(x)=\frac{1+\cos(2\pi x)}2$ and $f^n=f\circ f^{n-1}$. Is it true that for almost every $x$, $\lim_{n \to \infty} f^n(x)=1$?
14
Given a sequence with $a_1=1$ and $a_{n+1}=a_n-\frac13a_n^2$. Is there an easier way to get an upper bound of $1/a_{100}$?
12
If $L^1$ average of $f$ is smaller than $t^2$ then $f=0$ a.e.