Anyone have time to check my Jacobian for this transformation?

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Discussion Overview

The discussion revolves around the calculation of the Jacobian for a transformation defined by the equations x = e^(u-v), y = e^(u+v), and z = e^(u+v+w). Participants are seeking verification and assistance with their calculations, expressing doubts about their results.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant initially claims their Jacobian is zero, expressing doubt about this result.
  • Another participant suggests that the Jacobian cannot be zero and encourages checking calculations for possible errors.
  • A participant admits to a mistake and proposes a new expression for the Jacobian, but later corrects it again.
  • Another participant points out a typo in a previous response and suggests a method involving finding all nine derivatives to clarify the calculation.
  • A participant reflects on the difficulty of the current material compared to previous coursework, indicating a need for assistance.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correct Jacobian value, with multiple competing calculations presented and ongoing corrections to earlier claims.

Contextual Notes

There are indications of potential errors in calculations and typographical mistakes, as well as varying levels of confidence among participants regarding their results.

Who May Find This Useful

Students and individuals studying calculus or related fields who are working on Jacobians and transformations may find this discussion relevant.

Theelectricchild
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Anyone have time to check my Jacobian for this transformation!?

[tex]x = e^{u-v}[/tex] [tex]y = e^{u+v}[/tex] [tex]z = e^{u+v+w}[/tex]

I ended up getting the Jacobian as ZERO.

This is why I am doubting myself--- it seems wrong! What do you guys get?

Thanks for you help. :redface:
 
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the jacobian isn't zero, check your calculations, you might have a bad sign...
 
Yeah i screwed up --- i got something like 2^(u-v) * (e^2u+2v+w)

does that look oK?
 
whoops i mean [2*e^(u-v)] * [(e^2u+2v+w)]
 
You still may be off: I get 2eu+v+we2u= 2e3u+v+w.

(Edited after jdavel pointed out an error.)
 
Last edited by a moderator:
Halls of Ivy,

You have a typo in your final answer. That should be 3u, not 2u.

Theelectricchild, to keep from confusing the signs, it helps (at least in this case, since exp(x) is its own derivative) to find all nine derivates and then write the determinant in terms of x, y and z. Then, with those two beautiful zeros, the Jacobian = 2xyz is almost staring you in the face.
 
Last edited:
Thx for your help guys--- I find this class a big leap in difficulty from where we left off in our calculus III course which was on tangent planes--- I am glad I am getting help. Ugh now to get ready for Friday's midterm.
 

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