Invariance of lagrangian with $\frac{d}{dt}(f(q,t))$
4421
Proof that total derivative is the only function that can be added to Lagrangian without changing the EOM
150081
Deriving Lagrangian density for electromagnetic field
28935
Lagrangian of the Euler equations
46593
Upper limits for jerk and higher derivatives in physics
114562
Boundary conditions for calculus of variations in phase space and under canonical transformations
59409
Show Laplace operator is rotationally invariant
27812
Understanding the differential $dx$ when doing $u$-substitution
77338
Lagrangian interpolation: degree of the interpolation polynomial
116427
$(c^{\mu}\partial_{\mu}-m)\phi(x)=0$ not Lorentz-invariant?
116612
Differential euqation for a pendulum: $ {d^2\alpha \over dt^2} + {g \over L} \cdot \alpha = 0 $
152809
A question concerning the Galilean invariance of Newton's laws
141643
Showing $\rho (x,y)=\frac{d(x,y)}{1+d(x,y)}$ is a metric
112073
What does a Lagrangian of the form $L=m^2\dot x^4 +U(x)\dot x^2 -W(x)$ represent?
71885
Derivatives of $ \frac{1}{r} $ and Dirac delta function
114505
Initial value problem $t\frac{dx}{dt}=x+\sqrt{t^2+x^2}$
56275
Vector derivative w.r.t its transpose $\frac{d(Ax)}{d(x^T)}$
94173
Deriving the Lagrangian for a free particle