https://www.lucaspauker.com/pdes PDEs You Should Know Wave Equation $$ \frac{\partial^2 u}{\partial t^2} = c^2 \frac{\partial^2 u}{\ partial x^2} $$ Simple Harmonic Motion $$ m \frac{d^2 x}{d t^2} = -kx $$ Heat Equation $$ \frac{\partial u}{\partial t}=\nabla^2 u $$ Laplace/Poisson Equation Poisson: $$ \nabla^2 f = h $$ Laplace: $$ \nabla^2 f = 0 $$ Maxwell's Equations Gauss's law: $$ \nabla\cdot E = \frac{\rho}{\epsilon_0} $$ No magnetic monopoles: $$ \nabla\cdot B = 0 $$ Faraday equation: $$ \ nabla\times E=-\frac{\partial B}{\partial t} $$ Ampere equation: $$ \ nabla\times B=\mu_0(J + \epsilon_0\frac{\partial E}{\partial t}) $$ Schrodinger Equation $$ i \hbar\frac{\partial \Psi}{\partial t} =-\frac{\hbar^2}{2m}\frac {\partial^2\Psi}{\partial x^2}+V\Psi $$ Black Scholes Equation $$ \frac{\partial V}{\partial t} + \frac{1}{2}\sigma^2S^2\frac{\ partial^2 V}{\partial S^2} +rS\frac{\partial V}{\partial S} - rV = 0 $$