Find the points on the surface closest to the origin

Click For Summary
SUMMARY

The discussion focuses on finding the points on the surface defined by the equation z² = xy + 4 that are closest to the origin using optimization techniques. Participants suggest employing the Lagrange multiplier method to minimize the distance function r² = x² + y² + z² while adhering to the surface constraint. One user emphasizes that minimizing r² simplifies the calculations compared to minimizing the square root of the distance. A reference link to a resource on Lagrange multipliers is also provided for further guidance.

PREREQUISITES
  • Understanding of Lagrange multipliers
  • Familiarity with multivariable calculus
  • Knowledge of distance minimization techniques
  • Ability to manipulate algebraic equations
NEXT STEPS
  • Study the application of Lagrange multipliers in optimization problems
  • Explore the concept of distance minimization in multivariable calculus
  • Review examples of constrained optimization problems
  • Investigate resources on surface equations and their properties
USEFUL FOR

Students and professionals in mathematics, particularly those studying calculus and optimization techniques, as well as anyone interested in solving constrained optimization problems in multivariable contexts.

EgyptMind
Messages
3
Reaction score
0
1. Homework Statement
find the points on the surface z^2=xy+4 closest to the origin

i tried the distance formula but it got too messy, i think there's an approach using lagrange multiplier but i just can't quiet figure it out...?
 
Last edited:
Physics news on Phys.org
to use lagrange, write the function you are trying to minimise (distance to origin r^2 = x^2 + y^2 + z^2), and use the surface as the constraint
 
a little more details...?
 
what have you tried? post #2 outlines a method to attempt
 
if you;re not sure about lagrange multipliers, try a google search, i found
http://www.uAlberta.ca/MATH/gauss/fcm/calculus/multvrbl/basic/Extrema/Lgrng_mltplrs_exmpl.htm
 
Last edited by a moderator:
EgyptMind said:
1. Homework Statement
find the points on the surface z^2=xy+4 closest to the origin

i tried the distance formula but it got too messy, i think there's an approach using lagrange multiplier but i just can't quiet figure it out...?
What did you try? If you use lanedance's suggestion, to minimize x^2+ y^2+ z^2 rather than \sqrt{x^2+ y^2+ z^2} (whatever minimizes one minimizes the other) it should not be "too messy".
 

Similar threads

Replies
3
Views
10K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
1
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
25K