Solution of Basel problem by Euler (from wikipedia)

Basel problem: find the exact value of $$1+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+… = ?$$ Solution: We have by Taylor expansion: $$\sin(x)=x-\frac{x^3}{3!}+\frac{x^5}{5!}-\frac{x^7}{7!}+…$$ Dividing through x we have, $$\frac{\sin(x)}{
Xu Cui
26 sec read

i to i

What is the value of $$i^i$$ \(i\) being the imagery unit. This beautiful number indeed equals to $$i^i=e^{-\pi/2}=0.2079…$$
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4 sec read

What can you do with 25 lines of actionscript?

http://www.25lines.com/
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0 sec read

April’s drawing

Dragon’s Cave by ~degarnemai on deviantART The above drawing is made by April my cousin.
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3 sec read

3D racing game (flash)

Or you can play it here: http://www.gamesfreak.net/games/3D-Rally-Racing_261.html
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2 sec read

Advantage and Disadvantage of NIRS over fMRI

Advantages cheaper portable (smaller) safe natural settings (e.g. real human interactions instead of computer presentation) high temporal resolution (10Hz) less sensitive to head motion clinically friendly less environment noise long time recording c
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18 sec read

Transparent windows with the mx:Window

You set systemChrome=”none” but it still doesn’t work? You probably forget to set showFlexChrome="false"
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3 sec read

localToGlobal doesn’t work

You need to make sure you don’t call localToGlobal too early. If you call this function in creationComplete event of the application, you will probably fail.
Xu Cui
5 sec read