Central force problem

This article consists of my comprehensive pdf notes I have made for central force problem in classical mechanics, without problems or exercises. The approach is primarily based on Lagrangian dynamics. We must understand that it is not necessary to treat it that way, eventhough we get all the desired results using calculus and Newton's laws like Kleppner and Kolenkow textbook deals it. But then why did I choose it to study it using Lagrangian dynamics? Because it gives deeper insights onto cyclic coordinates and reduction of number of degrees of freedom using symmetry arguments. It is beautiful that way and also more convincing. If you are a problem solver looking to apply this knowledge of central force,I suggest you to solve David Morin's exercises and examples once you go though this. 

Note: I didn't follow Goldstein for making this notes.This notes consits of little less rigorous treatment compared to it,but suffices for anyone who's studying it for cracking some competitive exam like NET,GATE like me. This notes is primarily made from nptel course of theoretical mechanics by Dr.Charudutt kadolkar and also from Marion Thompton(the integral orbit equation and Bertrand's theorem on closed orbits and method of undetermined coefficients to solve equation of orbit). Here is the link. Any doubts, criticism,praises and paisa are always welcome.Cheers!

https://documentcloud.adobe.com/link/track?uri=urn:aaid:scds:US:bc20370c-1bff-4d68-84af-d01111762be1