## math

两千多年前的战国时期，魏王的大臣庞葱对魏王说：“如果有人说外面的街市有老虎，您相信吗？”魏王说不信。“如果又有一个人说呢？”魏王说：“我将半信半疑。”“如果有第三个人说呢？”魏王说：“我会相信。” 上
I used to use jsMath to support latex in this website, but it no longer works (I have no idea why). The one I am using right now in this blog is MathJax LaTex WordPress plugin. A pleasant surprise is that my old equations (e.g. in Balloon model) stil
When I was in high school and saw the following equation, my mind was blown! $$1+\frac{1}{4}+\frac{1}{9}+\frac{1}{16}+…=\frac{\pi^2}{6}$$ Why is Pi here? Isn’t it supposed to show up only in circle related problem? But the left-hand has n
Laplace introduced the sunrise problem in 18th century. With prior knowledge that the sun has risen N days in the past consecutively (not knowing the gravity rules etc), what is your confidence that the sun will rise tomorrow? Let p be the probabilit