Consider a particle moving in one dimension, with coordinate x and velocity ˙x.
Suppose that the particle moves in a potential
U(x) = 1/2 (kx^2) for constant k
(a) Find the Lagrangian function L( ˙x, x).
(b) Using the Euler-Lagrange equation, find the equation of motion for
the coordinate x.
(c) Solve the equation of motion of part (b) to find the trajectory x(t),
for initial conditions x(0) = A, ˙x(0) = 0.