$F = ma$
$E=mc^2$
$$ \frac{\partial L}{\partial w_{ij}} = \sum_{n=1}^{N} (y_n - \hat{y}_n) \frac{\partial \hat{y}_n}{\partial w_{ij}} $$
$$ \int_a^b f(x) dx = f(\xi) · (b - a) , \text{where } \xi \in (a,b) $$
$$ \begin{cases} \nabla \cdot \mathbf{E} = \frac{\rho}{\varepsilon_0} & \text{} \\ \nabla \cdot \mathbf{B} = 0 & \text{} \\ \nabla \times \mathbf{E} = - \frac{\partial \mathbf{B}}{\partial t} & \text{} \\ \nabla \times \mathbf{B} = \mu_0 \mathbf{J} + \mu_0 \varepsilon_0 \frac{\partial \mathbf{E}}{\partial t} & \text{} \end{cases} $$