\lim_{x\rightarrow 0,~y \rightarrow 0} f(x, y)
\lim_{\substack{x\rightarrow 0\\y\rightarrow 0}} f(x,y)
\int_{0}^{1} \frac{x}{\sqrt{a^2 + x^2}} dx = \left[ \sqrt{a^2 + x^2} \right]_{0}^{1}
2\pi\sqrt{l/g}
\gamma \equiv \frac{1}{\sqrt{1 - v^2/c^2}}
\lambda_j = \vec{\lambda} \cdot \vec{e}_j
\begin{array}{r l r l}
u &= \ln x \quad & dv &= x\,dx \\
du &= \frac{1}{x}\,dx & v &= \frac{1}{2} x^2
\end{array}
e^x = \sum_{n=0}^\infty \frac{x^n}{n!} = \lim_{n\rightarrow\infty} (1+x/n)^n
e^x = \sum_{n=0}^\infty \frac{x^n}{n!} = \lim_{n\rightarrow\infty} (1+x/n)^n
f(x + \Delta x) = f(x) + f'(x) \Delta x + \varepsilon(\Delta x) \Delta x
\begin{multline*}
\tan^n \theta=\tan^{n-2}\theta \tan^2 \theta\\ =\tan^{n-2}\theta(\sec^2\theta-1)=\tan^{n-2}\theta\sec^2\theta-\tan^{n-2}\theta
\end{multline*}
M^2 = \left(
\begin{array}{cc}
M^2_{11} & M^2_{18}\\
M^2_{18} & M^2_{88}
\end{array}
\right)
M^2_{88} = \frac {1}{3} \left(4m^2_{K} - m^2_{\pi}\right)
M^2_{11} = m^2_{\eta} + m^2_{\eta'} - M^2_{88}
M^2_{18} = - \sqrt{(M^2_{88} - m^2_{\eta})(m^2_{\eta'} - M^2_{88})}
\begin{multline*}
\eta = \eta_{8}\cos\theta_{P} - \eta_{1}\sin\theta_{P}\\
\eta' = \eta_{8}\sin\theta_{p} + \eta_{1}\cos\theta_{P}
\end{multline*}
\eta_{1} = \frac {u\bar{u} + d\bar{d} + s\bar{s}}{\sqrt{3}},
\eta_{8} = \frac {u\bar{u} + d\bar{d} - 2s\bar{s}}{\sqrt{6}}
\binom{n}{m}=\binom{n}{n-m}
3^n = \sum_{m=0}^n \left( \binom{n}{m} \cdot \sum_{p=0}^m \binom{m}{p} \right)
\begin{align*}
D^{-\nu}e^{at}&=\frac{1}{\Gamma(\nu)}e^{at}\int_0^t x^{\nu-1}e^{ax}\;dx \\
&=E_t(\nu,a)
\end{align*}
x = \frac{-b \pm \sqrt{b^2 - 4 a c}}{2 a}
d = \frac{1}{2}a t^2
\sum F = ma
\lim_{x\rightarrow c} f(x) = L
0 \leq |x - c| \leq \delta
|f(x) - L| \leq \epsilon
F_g = G \frac{m_1 m_2}{d^2}
\displaystyle{\int_2^4 {\left[ {8(t - 2)} \right]^{-0.5} dt = } \left[ {\frac{1}{{\sqrt 2 }}(t - 2)^{0.5} } \right]_2^4 = 1}
\int_M d\omega =\int_{\partial M}\omega
I=\frac{V_{out}-V_{LDR}}{R_1}
R_{LDR}=\frac{V_{LDR}R_1}{V_{out}-V_{LDR}}
R_1=\sqrt{(10^7-\lim_{R\rightarrow 0})}
R=-1\frac{1}{13}(lux)+4\frac{4}{13}
R=\frac{160-14(lux)}{13}
R=e^{\frac{160-14ln(lux)}{13}}
\frac{\pi}{6}(0.3)^{3}(7.07)g=\frac{\pi}{6}(0.3)^{ 3}(1.26)g+3\pi(0.88){u}(0.3)
i\hbar\frac{\partial\Psi}{\partial t} = \frac{\hbar^2}{2m}\frac{\partial^2\Psi}{\partial x^2} + V\Psi
det[\partial^2 + m^2]
\gamma \equiv \frac{1}{\sqrt{1 - v^2/c^2}}