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Qiaochu Yuan

Berkeley, CA

math.berkeley.edu/~qchu

Age: 22

I'm a second-year graduate student in pure mathematics at UC Berkeley. You can contact me at qchu[at]math[dot]berkeley[dot]edu.

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Top Questions
73 votes

Intuition for the definition of the Gamma function?

probability-theory intuition gamma-function asked Aug 27 '10 at 5:01
math.stackexchange.com

42 votes

Quadratic reciprocity via generalized Fibonacci numbers?

number-theory combinatorics fibonacci-numbers asked Aug 14 '10 at 18:58
math.stackexchange.com

36 votes

What's the point of studying topological (as opposed to smooth, PL, or PDiff) manifolds?

general-topology manifolds motivation asked Feb 4 '11 at 22:33
math.stackexchange.com

31 votes

Who's the brown dinosaur in Braid?

braid asked Aug 8 '11 at 15:04
gaming.stackexchange.com

30 votes

What is the spectral theorem for compact self-adjoint operators on a Hilbert space actually for?

big-list functional-analysis examples-counterexamples asked Nov 30 '10 at 22:57
math.stackexchange.com

29 votes

What structure does the alternating group preserve?

combinatorics group-theory category-theory groupoids asked Sep 22 '10 at 1:41
math.stackexchange.com

25 votes

“Cayley's theorem” for Lie algebras?

abstract-algebra lie-algebras asked Aug 22 '10 at 15:22
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25 votes

What's a good way to write “x does not divide y”?

math-mode symbols relation-symbols asked Oct 23 '10 at 22:17
tex.stackexchange.com

22 votes

How do I count the subsets of a set whose number of elements is divisible by 3? 4?

number-theory combinatorics binomial-coefficients asked Jul 28 '10 at 5:32
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22 votes

Norms on C[0, 1] inducing the same topology as the sup norm

homework real-analysis functional-analysis banach-spaces asked Jan 5 '11 at 16:24
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Top Answers
258
Mathematical difference between white and black notes in a piano
math.stackexchange.com

142
Does Pi contain all possible number combinations?
math.stackexchange.com

94
Is it possible to represent every huge number in abbreviated form?
math.stackexchange.com

85
Proof that $C\exp(x)$ is the only set of functions for which $f(x) = f'(x)$
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84
Is infinity a number?
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73
Could I be using proof by contradiction too much?
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63
Why is a circle in a plane surrounded by 6 other circles
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63
Given an infinite number of monkeys and an infinite amount of time, would one of them write Hamlet?
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62
How many sides does a circle have?
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60
Is it generally accepted that if you throw a dart at a number line you will NEVER hit a rational number?
math.stackexchange.com

52
A challenge by R. P. Feynman: give counter-intuitive theorems that can be translated into everyday language
math.stackexchange.com

44
How do I explain 2 to the power of zero equals 1 to a child
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44
Can someone explain the math behind tessellation?
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39
What is the Riemann-Zeta function?
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39
Tablet for reading textbooks and writing math by hand?
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39
Is a counterexample considered a rigorous proof that a property is not true?
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38
Interesting results easily achieved using complex numbers
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38
Why bother with Mathematics, if Gödel's Incompleteness Theorem is true?
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36
Nice expression for minimum of three variables?
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36
Non-Scientific questions solved by mathematics
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36
What is the practical difference between a differential and a derivative?
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34
Getting better at proofs
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34
Why everytime the final number comes the same?
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33
Why are differentiable complex functions infinitely differentiable?
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33
Different methods to compute $\sum\limits_{n=1}^\infty \frac{1}{n^2}$
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33
Is there any geometric way to characterize $e$?
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33
Should the notation $\int_{0}^{x} f(x) dx$ be frowned upon?
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31
Why does this converge to $\pi/4$?
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31
How does one know that a theorem is strong enough to publish?
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30
Proofs that every mathematician should know?
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