The Path Inetgral and Classical Lagrange

[Quarlep]

I know that The path Integral becames classical Lagrange (Classic Mechanics) how can it be turn it.

 

[atyy]

The classical solution is the saddle point approximation to the path integral.

http://www.nyu.edu/classes/tuckerman/stat.mechII/lectures/lecture_13/node2.html
http://www-thphys.physics.ox.ac.uk/people/FabianEssler/C6web2012/theory/quantumpath.pdf

 

[Quarlep]

I dont have enough math to understand it

 

[atyy]

Roughly the idea is:
We associate a number with every possible path.
In classical mechanics, there is only one correct path.
In quantum mechanics, there is no single correct path, and we sum over all paths. The classical path is the path with the largest contribution to the sum.