Derivation of the one dimensional Euler–Lagrange equation

Derivation of the one dimensional Euler–Lagrange equation

################################
Quantum Mechanics:
https://www.youtube.com/playlist?list=PLg9w7tItBlZuP5Wv2jMbeTd7uc9ZXYS6m

Electrodynamics:
https://www.youtube.com/playlist?list=PLg9w7tItBlZu6oIdAtRaT-Wtjkg3_dJcQ

Quantum Information:
https://www.youtube.com/playlist?list=PLg9w7tItBlZs2JgNL6qxtPSlnWAFkqoJG

Quantum Algorithms:
https://www.youtube.com/playlist?list=PLg9w7tItBlZvyCUpJAskKqpeLkKhrtQio