I've just started reading Feynman and Hibbs path integrals and Quantum mechanics after a decade hiatus from my undergraduate math degree (including a few semesters of physics for engineers). It would be tremendously helpful to see the step by step solutions to some of the first set of problems (Page 27-28, #2.1 and on) As many as folks are willing to post! Or if anyone knows of the solutions being available on-line that would also be helpful.
The specific concept question is finding the extremum of functional that is the integral of the lagrangian of a system (classical action). The easiest example is 2.1, show that for $L=m/2 (dx/dt)^2$, the extremum is $m/2*(x_b-x_a)^2/(t_b-t_a)$. I have tried manipulating the integral by replacing 'partial of $L$ with respect to $x$' with '$d/dt$ (partial $L$ with respect to $dx/dt$) but haven't gotten there. I know it's the easiest problem but I think if I see an example, I will be able to apply what I learn to the harder subsequent problems
I hope that's enough to come off "hold" Thanks!
