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seen Dec 5 '13 at 4:34

Systems biologist.


Nov
9
comment Equivalent conditions to $0\leq x+\frac{1}{2}x(1-x)a\leq 1$?
@JavaMan Not necessarily "opening downwards" -- if $a<0$.
Nov
9
answered Equivalent conditions to $0\leq x+\frac{1}{2}x(1-x)a\leq 1$?
Nov
9
revised Interpreting division
added 37 characters in body
Nov
9
answered Interpreting division
Nov
9
comment How can I solve this system?
Plugging the 1st and 2nd equations into the 3rd, we get a quadratic equation for y.
Nov
9
revised Hard algebra problem
added 351 characters in body
Nov
9
revised Hard algebra problem
added 351 characters in body
Nov
9
revised Hard algebra problem
added 158 characters in body
Nov
9
revised Hard algebra problem
deleted 2 characters in body
Nov
9
answered Hard algebra problem
Nov
9
comment How could we find the largest number in the sequence $ \sqrt{50},2\sqrt{49},3\sqrt{48},\cdots 49\sqrt{2},50$?
Note that if the original question is for example $n\sqrt{50-n}$ instead of $n\sqrt{51-n}$, no integer $n$ satisfies the equality of the AM-GM inequality; in that case, a more careful evaluation, such as that used in Jyrki Lahtonen's answer, is needed.
Nov
8
awarded  Nice Answer
Nov
8
accepted Calculating the probability that a cord makes a knot
Nov
8
comment Calculating the probability that a cord makes a knot
Thanks so much, that's what I'm looking for. If you post your comment as an answer I'll accept it.
Nov
8
answered How could we find the largest number in the sequence $ \sqrt{50},2\sqrt{49},3\sqrt{48},\cdots 49\sqrt{2},50$?
Nov
7
comment Is there a good online dictionary/encyclopedia for mathematics?
If you read Japanese, the most recent (Japanese 4th) edition of the Encyclopedic Dictionary of Mathematics has an accompanying CD-ROM that contains PDF files of the 4th and 3rd (equivalent to English 2nd) edition, which I find extremely convenient. (But of course they are not for free.)
Nov
7
comment Proving a large factorial expression for $1 \le m \le n - 1$
math.stackexchange.com/questions/70190/…
Nov
7
comment Higher order derivative of parameter curves
$\frac{d^2y}{dx^2}=\frac{d}{dx}\left(\frac{dy}{dx}\right)$, and $\frac{d}{dx}(\cdots)=\frac{dt}{dx}\frac{d}{dt}(\cdots)$
Nov
7
revised Mathematics and Music
added 36 characters in body
Nov
7
answered Mathematics and Music