I don't know which it was but Dr. Jorge Diaz has an excellent video on Lagrangian mechanics as part of a series on quantum mechanics (this video just pertains t

I don't know which it was but Dr. Jorge Diaz has an excellent video on Lagrangian mechanics as part of a series on quantum mechanics (this video just pertains to the formalism applicable classically) https://www.youtube.com/watch?v=QbnkIdw0HJQ https://www.youtube.com/watch?v=QbnkIdw0HJQ