Question

What are all the applications that can take advantage of a Larange Multiplier?

Answer 1

lagrange even lol

Answer 2

min/max

Answer 3

min max is one; any others?

Answer 4

and how would you go about finding a min with it?

Answer 5

you can't find min/max, just extrema

Answer 6

so when you find a extrema, compare with other point to see if it is min or max

Answer 7

any other application
Where two gradient vector are same direction

Answer 8

I was trying to see if i could use it last night to solve a system of equations :) dint work as i expected lol

Answer 9

f(x,y) = 3x-4y - 20
g(x,y) = 2x +y +3

F(x,y,L) = 3x-4y - 20 - L(2x +y +3) :)

Answer 10

Fx = 3-2L = 0

L = 3/2

Fy = -4-L = 0

L = -4

FL = 2x+y+3 = 0 .....

Answer 11

but since there is no spot for the gradients to be the same; i guess it just wont pan out

Answer 12

As you can see from picture , there are no places where gradient vector are in same direction

Answer 13

yep; that was my conclusions as well ;)

Answer 14

That's interesting because if it were a min/max function with one plane a constraint, it wouldn't work

Answer 15

even if there was a point of common gradience; the points of intersection required from a system of equations would not be condusive to a lagrange multi ... :)

Answer 16

a lagrange is useful in finding the common point that 2 systems have in tangency to each other; where they softly touch ...

finding secants and chords requires something else i believe

Answer 17

you take the cross product of two gradient vector
{3,4}x{2,1}

Answer 18

like this
http://openstudy.com/users/eseidl#/users/eseidl/updates/4e3ec3180b8ba3ff6fa91d15

Answer 19

also known as the determinant right?

34
21

3 - 8 = -5