1. The problem statement, all variables and given/known data [PLAIN]http://img96.imageshack.us/img96/9288/lagrangiansimplifcation.jpg [Broken] "[URL [Broken] If you require more info in the derivation, it's on page 1: http://www.ph.qmul.ac.uk/~phy304/Homework/HW3sol.pdf 2. Relevant equations L = T - V 3. The attempt at a solution I understand exactly the process of obtaining the Lagrangian... But I do not understand his simplifying process at all. Could somebody please help/forward me into the right direction? Thanks in advance!