From the plot of U(x) vs. x of Problem, determine the period from the equation
![2009_Question.png](https://secure.tutorsglobe.com/CMSImages/2009_Question.png)
(Remember that E in the text was for a unit mass.)
Problem
Plot the phase plane trajectory for the undamped spring-mass system, including the potential energy curve U(x). Discuss the initial conditions associated with the plot.