Partial Differentiation on the Wave Equation
95774
$\frac{\partial^2 u}{\partial t^2}-c^2\frac{\partial^2u}{\partial x^2}=0\text{ implies } \frac{\partial^2 u}{\partial z \partial y}=0$
77388
Differentiation operator and eigenvalues
93967
Prove partial derivatives exist, but not all directional derivatives exists.
52701
Manipulating Partial Derivatives of Inverse Function
25164
Velocity-Dependent Potential and Helmholtz Identities
13727
Wave equation: $y=A \sin(\omega t-kx)$ or $y=A\sin(kx-\omega t)$?
27812
Understanding the differential $dx$ when doing $u$-substitution
138766
Nondimensionalizing a differential equation
40908
Raised index of partial derivative
90287
How to derive $[x_i, F(\vec p)] = i \hbar \frac {\partial F(\vec p)}{\partial p_i}$
32209
Labeling solutions of an Eigenvalue equation involving Bessel functions
69945
A PDE exercise from Gilbarg Trudinger. problem 2.2
134433
Differentiation - simple case
47168
PDE separation of variables
99532
Mathematical precise definition of a PDE being elliptic, parabolic or hyperbolic
114562
Boundary conditions for calculus of variations in phase space and under canonical transformations
893
Simple PDE with Neumann BC