Problems for the 34th IYPT 2021
http://ahhafree.blogspot.com/2019/04/ubuntu-boot-loader.html
ShareLatex (on line)
The Not So Short Introduction to LATEX 2ε
http://tug.ctan.org/info/lshort/english/lshort.pdf
Pretty Much Physics
https://www.youtube.com/channel/UCVa8De6q6aOjtx_TEiDBaMw
https://www.youtube.com/watch?v=NOMUnMuxDZY
https://www.youtube.com/watch?v=nzmJb7KITxc&list=PLOzRYVm0a65dGef0BEA_CWbVCO6BtMZhE&index=1
https://www.impan.pl/~feliksp/holomorf-past.html
https://matthewjacques.info/
Pramod Padmanabhan (semigroup)
如何手動清除 Windows 10 暫存檔案?
https://helpcenter.trendmicro.com/zh-tw/article/tmka-08271/
https://sofree.cc/win10-quick-file/
https://support.microsoft.com/zh-tw/help/4026529/windows-10-using-system-file-checker
http://www.yesio.net/utv.php?utno=18&pjno=6
https://drive.google.com/file/d/1erTLaUER6jFFf4VWZUI3pHtsmMlk2tIE/view
http://ioflex.yesio.net/node/myDevices
使用範例程式
#upload.py
# get mac address
import yesio.Cloud as cl
print(cl._wifi_get_mac())
os
– basic “operating system” servicesFusion
123D
陳富國 Fusion
https://drive.google.com/file/d/0ByS7PYyDiBW8V3ZZU0pFUlVFVVU/view
http://www.1zlab.com/wiki/micropython-esp32/pwm/
C:(x-1)^2+(y-2)^2=4
A=(1,4)
B=(2,4)
1.過A求圓的切線(check A on C)
方法一.點到直線距離=r ( d(O,L)=r )
check A on C ?
(1-1)^2+(4-2)^2=4, so A on C
L: y-4=m(x-1)
mx-y-m+4=0
O=(1,2), r=2
d(O,L)=|m-2-m+4|/sqrt(m^2+1)=2
2/sqrt(m^2+1)=2
2=2 * sqrt(m^2+1)
m=0
L: y-4=0
方法二. 直線的向量與半徑的向量內積為零 ( L.r=0 )
vector L=(x-1,y-4)
vector r=A-O=(0,2)
L.r=0
2(y-4)=0
y-4=0
2.過B(2,4)求圓的切線(check B doesn't on C)
方法一.點到直線距離=r ( d(O,L)=r )
L: y-4=m(x-2)
mx-y-2m+4=0
O=(1,2), r=2
d(O,L)=|m-2-2m+4|/sqrt(m^2+1)=2
|-m+2|=2*sqrt(m^2+1)
m^2-4m+4=4(m^2+1)
3m^2+4m=0
m=0,-4/3
y-4=0
or
y-4=-4/3(x-2)
4x+3y-8-12=0
4x+3y-20=0
方法二. 直線的單位法向量與半徑的向量內積=半徑 ( n.r=半徑 )
L: y-4=m(x-2)
mx-y-2m+4=0
vector n=(m,-1)/sqrt(m^2+1)
vector r=(x-1,y-2)
n.r=2
|m(x-1)-(y-2)|/sqrt(m^2+1)=2
|mx-y-m+2|=2*sqrt(m^2+1)
|2m-4-m-2|=2*sqrt(m^2+1)
|m-2|^2=4(m^2+1)
m^2-4m+4=4m^2+4
3m^2+4m=0
m=0,-4/3
y-4=0
or
y-4=-4/3(x-2)
4x+3y-8-12=0
4x+3y-20=0
sudo apt-get install flatpak
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
flatpak install flathub org.octave.Octave
flatpak run org.octave.Octave
https://ubuntuqa.com/zh-tw/article/9289.html