Physics, Lagrangian, Symmetry, Classical Mechanics, Mechanics.
Principle of Stationary Action (Briefly) In the previous article, I explained the principle of stationary action. It states that a system described by generalized coordinates q(t) = (q₁,…,qₙ) is such that, if q(t) is the true evolution of the system, to the first order, the action S[q] does not