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ak-47

If you could write the Euler-Lagrange equation on the board during the test it'd be awesome. I imagine a lot of us will forget it on our post-it notes.

Sohil

Is there a good way to think conceptually of what a Lagrangian represents? Without explaining it in too much math, why is it K-U? I can see what the Lagrangian is in terms of the equations, but I don't have an intuitive idea about it.

dsaksena

Ah the correct slide, a proof is given here (in like first 12 pages) for Euler-Lagrangian equation.

http://www.cs.cmu.edu/~me/811/notes/Variations.pdf

refrence : 16-811 Math Funda for Robotics CMU

ak-47

@Sohil It is just another way of writing Force=Mass*Acceleration.

I think the reason it exists is because now we just have a bunch of derivatives on a single quantity, so we can solve problems with our differential equations toolbox.

kmcrane

Really understanding this stuff takes a bit more work; you might want to start with the Wikipedia page for Lagrangian mechanics.