Consider two pendulums of length L connected by a spring with spring constant k placed at a distance a from the pivot point of the pendulum.
a) Using Lagrangian Mechanics, show that the equations of motion of the two pendulums are given by:
mLθ'' + mgLsinθ - ak(θ1 - θ2) = 0
mLθ'' + mgLsinθ + ak(θ1 - θ2) = 0
b) Derive the same equations using Newton's 2nd Law.