Distinguishing Max, Min & Saddle - Choosing Coordinate Systems

  • Context: Undergrad 
  • Thread starter Thread starter MarianaA
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Discussion Overview

The discussion revolves around distinguishing between maximum, minimum, and saddle points in mathematical analysis, as well as the appropriate contexts for using different coordinate systems (rectangular, cylindrical, and spherical) in problem-solving.

Discussion Character

  • Technical explanation
  • Homework-related
  • Conceptual clarification

Main Points Raised

  • One participant inquires about how to distinguish between maximum, minimum, and saddle points.
  • Another participant suggests starting with definitions for each type of point.
  • A different participant provides a technical explanation that a minimum occurs when the Hessian is positive definite, a maximum when it is negative definite, and a saddle point when the Hessian has both positive and negative eigenvalues.
  • Regarding coordinate systems, one participant notes that cylindrical coordinates are advantageous for systems symmetrical about an axis, while spherical coordinates are better for point-symmetrical systems, with rectangular coordinates being used for everything else.
  • There is a concern expressed by one participant about the thread potentially being deleted if it is considered homework-related.
  • Another participant confirms that they need this information for their homework.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and need for clarification, but there is no consensus on the definitions or applications discussed. The thread includes both exploratory questions and technical responses, indicating a mix of knowledge levels and perspectives.

Contextual Notes

Some definitions and concepts may depend on specific mathematical contexts or assumptions that are not fully articulated in the discussion.

MarianaA
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Hi every one, I have two questions, I hope some one can help me.
Thanks.

How can I distinguish between a maximum, minimum or a saddle?

When are times when a particular coordinate system is a better choice the n the other two (rectangular, cylindrical and spherical)?
 
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How can I distinguish between a maximum, minimum or a saddle?
You could start by writing out the definition for each.
 
but I don't know the definition
 
A minimum occurs when the Hessian is positive definite, a maximum when it is negative definite, and a saddle point when the Hessian has positive and negative eigenvalues.
 
Thanks ^_^
How about my second question:

When are times when a particular coordinate system is a better choice the n the other two (rectangular, cylindrical and spherical)?
 
I am assuming this is not homework. If it is, this thread will probably be deleted.
 
Well I need to know this so I can do my homework
Thanks ^_^
 

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