Introduction to the Lagrange Multiplier

This video gives a conceptual introduction to the Lagrange multiplier method of solving constrained optimization problems. It explains why the method is sometimes necessary, outlines why the method works, and then walks through the steps needed to solve for an optimum.

By Jodi Beggs - Economists Do It With Models

[curtmcd]

Best explanation I've seen yet. The geometric interpretation is essential. Few ever mention that the original constraint is partial lambda, so that all of the partials of L correspond to all of the equations to be solved. That's a beautiful thing. But also multiple constraints and shadow price, all in one video.

[ivanaskitchie]

Thank goodness for you and your wonderful vídeos 💝💝💝💝💝💝 some of us need this kind of tutoring, which helps us remember many previous mathematical concepts.

[JonAddison]

I was doing something completely different in mathematics, however this helped merely because your voice is so soothing, ha.

[BraveNewWorldSH]

@jodiecongirl It's an honors class. I am using the Acemoglu text and I can hardly get anything out of it. Thanks Jodi. Big fan!

[billhopkins]

I think that this is still one of the best explanations of the LM.

[그림일기-ks]

The best video explaining Lagrangian among those I've seen!

[doaaserageldin]

u nailed it !! even better than my professors all together !

[林某-px]

It is easier to convert practical problems into optimization problems than to convert them into PDE. Optimization is way more flexible. I gotta learn some optimization technique now, it is really powerful

[aristoi]

Nice video Jodie.Who knew economists make good math teachers.

[benwoodruff]

Jodi, that was a clear description. Keep up the good work!

[BraveNewWorldSH]

Hi Jodi, your videos are very helpful and useful. Thanks for the great work. Any chance you would do a video on Hamiltonian?

[Sanyat]

awesome explanation and graphical intuition!!

[jodiecongirl]

@nahaymath Either LaTex or the "Insert Equation" feature in newer versions of Word. I find the latter to be sufficient for the vast majority of purposes, and it's easy to either copy and paste into PowerPoint or take a screen shot of and turn into an image.

[jodiecongirl]

@BraveNewWorldSH Wow- I had no idea that there would be such demand for the more advanced concepts. Yeah, I can do that, so stay tuned. :)

[DaylightDigital]

8:57 You are correct, the Langrangian is not the same as a Lagrange Multiplier, which is also not the same as a Lagrange Point. J.L.L. was a prolific mathematician!!!

[sahb]

I love your videos, do you do shirts like yours? I'd love to get one.

[vangelismoulas]

minimizing free energies, or maximizing work in thermodynamics. subject to constraints like conservation of mass or total energy. cheers

[bennpackham]

Great video, but why are the gradient functions perpendicular to the utility curves and budget constraint at the optimal point? Cheers

[VideoOfMike]

I just wanna learn calculus from you all day....

[alahemy]

I am interested in the Hamiltonian too. Thanks