1.Sterling
n! \approx \sqrt{2 \pi n} \left( \frac{n}{e} \right)^n
n! \approx \sqrt{2 \pi n} \left( \frac{n}{e} \right)^n
2.Shrodinger 2
i\hbar\frac{\partial \psi}{\partial t}
= \frac{-\hbar^2}{2m} \left(\frac{\partial^2}{\partial x^2}
+ \frac{\partial^2}{\partial y^2}
+ \frac{\partial^2}{\partial z^2} \right)
\psi + V \psi
i\hbar\frac{\partial \psi}{\partial t} = \frac{-\hbar^2}{2m} \left(\frac{\partial^2}{\partial x^2} + \frac{\partial^2}{\partial y^2} + \frac{\partial^2}{\partial z^2} \right) \psi + V \psi
3.shrodinger
i\hbar\frac{\partial \psi}{\partial t}
= \frac{-\hbar^2}{2m} \left(\frac{\partial^2}{\partial x^2}
+ \frac{\partial^2}{\partial y^2}
+ \frac{\partial^2}{\partial z^2} \right)
\psi + V \psi
i\hbar\frac{\partial \psi}{\partial t} = \frac{-\hbar^2}{2m} \left(\frac{\partial^2}{\partial x^2} + \frac{\partial^2}{\partial y^2} + \frac{\partial^2}{\partial z^2} \right) \psi + V \psi
4.shannon
H(X) = – \sum_{i=1}^{N-1} p_i \ln p_i
H(X) = - \sum_{i=1}^{N-1} p_i \ln p_i
5.Merton
\begin{gather}
E = V_t N(d_1) – K \exp(-r\Delta T) N (d_2) \\
d_1 = \frac{\ln\frac{V_t}{K}
+ \left(r + \frac{\sigma_v^2}{2}\right) \Delta T}{\sigma_v\sqrt{\Delta T}} \\
d_2 = d_1 \sigma_v\sqrt{\Delta T}
\end{gather}
\begin{gather} E = V_t N(d_1) - K \exp(-r\Delta T) N (d_2) \\ d_1 = \frac{\ln\frac{V_t}{K} + \left(r + \frac{\sigma_v^2}{2}\right) \Delta T}{\sigma_v\sqrt{\Delta T}} \\ d_2 = d_1 \sigma_v\sqrt{\Delta T} \end{gather}
6.Maxwell
\nabla \cdot \vec{\bf E} = \frac {\rho} {\varepsilon_0} \\
\nabla \cdot \vec{\bf B} = 0 \\
\nabla \times \vec{\bf E} = – \frac{\partial\vec{\bf B}}{\partial t} \\
\nabla \times \vec{\bf B} = \mu_0\vec{\bf J} + \mu_0\varepsilon_0 \frac{\partial\vec{\bf E}}{\partial t}
\nabla \cdot \vec{\bf E} = \frac {\rho} {\varepsilon_0} \\ \nabla \cdot \vec{\bf B} = 0 \\ \nabla \times \vec{\bf E} = - \frac{\partial\vec{\bf B}}{\partial t} \\ \nabla \times \vec{\bf B} = \mu_0\vec{\bf J} + \mu_0\varepsilon_0 \frac{\partial\vec{\bf E}}{\partial t}
7.leibniz
(f \cdot g)^{(n)} = \sum_{k=0}^{n} \binom{n}{k}f^{(n-k)}g^{(k)}
(f \cdot g)^{(n)} = \sum_{k=0}^{n} \binom{n}{k}f^{(n-k)}g^{(k)}
8.Germain
\begin{gather}
x^4 + 4y^4 = \left( (x+y)^2 + y^2 \right)\left((x-y)^2 + y^2 \right) \\
= (x^2 + 2xy + 2y^2)(x^2 – 2xy + 2y^2)
\end{gather}
\begin{gather} x^4 + 4y^4 = \left( (x+y)^2 + y^2 \right)\left((x-y)^2 + y^2 \right) \\ = (x^2 + 2xy + 2y^2)(x^2 - 2xy + 2y^2) \end{gather}
9.Gauss
\Phi(c) = \frac{1}{\sigma\sqrt{2\pi}} \int_{-\infty}^{c} e^{-\frac{1}{2}\left(\frac{x-\mu}{\sigma}\right)^2}dx
\Phi(c) = \frac{1}{\sigma\sqrt{2\pi}} \int_{-\infty}^{c} e^{-\frac{1}{2}\left(\frac{x-\mu}{\sigma}\right)^2}dx
10.Fourier
\hat{f}(\xi) = \int_{-\infty}^{\infty} f(x) e^{-2\pi i x \xi}dx
\hat{f}(\xi) = \int_{-\infty}^{\infty} f(x) e^{-2\pi i x \xi}dx
11.Euler
e^{i\pi} + 1 = 0
e^{i\pi} + 1 = 0
12.Einsterin
t^{\prime} = \frac{ t – \frac{vx}{c^2} }{ \sqrt{ 1 – \frac{v^2}{c^2}} } \\
x^{\prime} = \frac{ x – vt }{ \sqrt{ 1 – \frac{v^2}{c^2}} } \\
y^{\prime} = y \\
z^{\prime} = z
t^{\prime} = \frac{ t - \frac{vx}{c^2} }{ \sqrt{ 1 - \frac{v^2}{c^2}} } \\ x^{\prime} = \frac{ x - vt }{ \sqrt{ 1 - \frac{v^2}{c^2}} } \\ y^{\prime} = y \\ z^{\prime} = z
13.Descartes
\begin{gather}
ax^2 + bx + c = 0 \\
x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}
\end{gather}
\begin{gather} ax^2 + bx + c = 0 \\ x = \frac{-b \pm \sqrt{b^2-4ac}}{2a} \end{gather}
14.Bayes
P(A~|~B) = \frac{P(B~|~A)P(A)}{P(B)}
P(A~|~B) = \frac{P(B~|~A)P(A)}{P(B)}