Quick Linear Integration Question

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    Integration Linear
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Discussion Overview

The discussion revolves around the process of linear integration involving an integrand expressed in terms of two components, F_y and F_x, over the hypotenuse of a right triangle. Participants explore the implications of breaking down the integrand into separate integrals and the challenges posed by the undefined nature of F and its dependencies.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant proposes breaking the integrand into two separate integrals for F_y and F_x, questioning the validity of this approach given the undefined nature of F.
  • Another participant expresses concern that F_x may depend on y and vice versa, complicating the separation of the integrals.
  • A participant shares their work on the problem and reflects on the choice of coordinates, suggesting that it may affect clarity but not the outcome.
  • There is a consideration of whether integration can proceed once a certain form is reached, specifically involving a ratio of integrals.
  • One participant realizes that they can replace variables with F_x and F_y to facilitate integration over dh, indicating a potential breakthrough in their understanding.
  • Another participant reiterates the concern about the dependencies of F_x and F_y on each other, questioning the correctness of their earlier statements.

Areas of Agreement / Disagreement

Participants express differing views on the validity of breaking the integrand into separate integrals due to the dependencies of F_x and F_y. The discussion remains unresolved as participants explore various approaches without reaching consensus.

Contextual Notes

Participants note the undefined nature of F and the implications of variable dependencies, which may limit the applicability of certain integration techniques. There are also references to the complexity introduced by the choice of coordinates.

sriracha
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If my integrand is:

[F_y (dy/dh) + F_x (dx/dh)] dh

Can I break this into two integrals, F_y over the y component of dh and F_x over the x component:

[F_y] (dh)_y + [F_x] (dh)_x

This is for linear integration over the hypotenuse of a right triangle with equal, undefined Δx Δy sides. F is also undefined.
 
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I guess this can't be right because F_x can depend on y and vice-versa. I will post the question and the work I have done. Please note this is not a homework assignment. I have looked at other similar problems, but none where F is undefined and this is what is giving me problems.
 
The problem is attached and I have uploaded my work here: http://i39.tinypic.com/kbd4s4.jpg

(I wanted to put it in high resolution and the file was too big for PF).
 

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By the way I arbitrarily chose the midpoint of the hypotenuse as my (x,y,z) although I realize now it would make things a bit clearer if I had chosen (x[itex]_{0}[/itex],y[itex]_{0}[/itex], z[itex]_{0}[/itex]). I'm pretty certain this should have no bearing on the work I did on the left.

I am wondering If I can go ahead and integrate once I have the problem solved to the point where I have [itex]\frac{1}{\Delta h}[/itex][itex]\int[/itex][itex]^{\Delta h}_{0}[/itex] F[itex]_{y}[/itex] - F[itex]_{x}[/itex] dh ?
 
That doesn't seem right either because then I'm left with F_y - F_x and I to integrate over h I think I would need to parametrize F_y and F_x. Even if I do, I am left with F_x and F_y of (deltay - h / deltah). I need a respective F_y (x,y,z) *deltay - F_x (x,y,z) * delta x and guess I have no idea how to get there.
 
Yay me! Where I found x = deltay - h/deltah and y = h/deltah I realized I could replace the x and ys with F_x and y with F_y then integrate over dh.
 
Also realized this is a "textbook type" problem so you can move it if you want.
 
http://www.infoocean.info/avatar1.jpg I guess this can't be right because F_x can depend on y and vice-versa.
 
Last edited by a moderator:
bwood01 said:
http://www.infoocean.info/avatar1.jpg I guess this can't be right because F_x can depend on y and vice-versa.

That's what I said.
 
Last edited by a moderator:

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