Specifically, the length of the spring on the left is d+ξn−ξn−1, where d is the distance between the masses in equilibrium, and the length of the spring on the right is \(d + \xi_{n+1...Specifically, the length of the spring on the left is d+ξn−ξn−1, where d is the distance between the masses in equilibrium, and the length of the spring on the right is d+ξn+1−ξn.