Lagrange multipliers

[Imum Coeli]

I am doing Multivariable Calculus through the MIT opencourseware. In the notes for example one http://ocw.mit.edu/courses/mathemat...ltipliers-and-example/MIT18_02SC_notes_21.pdf it seems that in the equation of gradient of f equals lambda gradient v (at the bottom of page one) they have substituted the incorrect value for dell f. I think it should be what they have above where gradient f equals <2x+3y,4z+3x,4y+2x>. This gives a final answer of x=2, y=1, z=3/2.

I was hoping that someone could please tell if they made a mistake or I made a mistake.

Thanks.

 

[MarkFL]

They have correctly stated \(\displaystyle \bigtriangledown f=\langle 2z+3y,4z+3x,4y+2x \rangle\) the first time, but then changed it at the bottom of the page, apparently a typo. Unfortunately, they went on to use this mistake to get an incorrect solution.

 

[Imum Coeli]

Thanks. It's a bit confusing when they make mistakes and I have no one else to ask. So your help is much appreciated.

Also, is there a way I can learn how to do that mathematical notation you used above for the gradient? It looks so much better.

 

[lookagain]

Also, is there a way I can learn how to do that mathematical notation you used above for the gradient?
It looks so much better.

Imum,

I looked at the text typed by that user. It is:


[t e x]\bigtriangledown f=\langle 2z+3y,4z+3x,4y+2x \rangle[/t e x]


However, type "tex" together and "/tex" together without any spaces between the characters.

 

[MarkFL]

An easy way to see the \(\displaystyle \LaTeX\) code used by someone, right-click the expression, then choose "Show Math As►TeX Commands".