Partial Differentiation without chain rule in Euler Lagrange Equations
7149
Calculus of variations -- how does it make sense to vary the position and the velocity independently?
105293
Proof of the second symmetric derivative
107290
proof of product rule of derivatives using first principle?
73045
Transitioning between Lagrangian and Eulerian fluid variables
105572
Independent Variables of a Lagrangian
53640
Equality of mixed partial derivatives
146540
Lagrange Multipler KKT condition
9403
Calculate Euler equations of fluid dynamics without division?
98358
A variational problem with a lagrangian , what is the lagrangian?
53616
Boundary condition with spatial derivative is ignored by NDSolve
4421
Proof that total derivative is the only function that can be added to Lagrangian without changing the EOM
36574
Does separation of variables in PDEs give a general solution?
13829
PDE list of equations, derivative for boundarry condition evaluates to true
84385
Implicit differentiation
125615
Defining the derivative without limits
73073
Differentiating $y=x^{2}$
150057
Approximating a three-times differentiable function by a linear combination of derivatives