Solving for y: Why/How do y and e^x switch places?

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Homework Help Overview

The discussion revolves around solving a differential equation involving the natural logarithm, specifically the equation ln((2y-1)/(y-1)) = x. The original poster is seeking clarification on the manipulation of the equation to isolate y and the reasoning behind the steps taken, particularly the switching of y and e^x.

Discussion Character

  • Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to understand the algebraic manipulation that leads to isolating y in the equation. They question the reasoning behind switching y and e^x and whether this relates to properties of inverse functions or graph symmetry.

Discussion Status

Participants are exploring the algebraic steps necessary to rearrange the equation. Some are seeking clarification on the nature of the equation and its transformation, while others provide general algebraic guidance without reaching a consensus on the underlying concepts.

Contextual Notes

There is uncertainty regarding the specific algebraic identities or methods used in the transformation of the equation, as well as the implications of graph symmetry on the manipulation of variables.

CINA
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Homework Statement



Doing a DE and need to solve for y, just wondering about this particular case.

Homework Equations



ln ((2y-1)/(y-1)) = x for y

The Attempt at a Solution



Wolfram says the result is: http://www.wolframalpha.com/input/?i=solve+ln+((2y-1)/(y-1))+=+x+for+y"

How/why did the y and e^x switch places? I know the first step is to exponentiate to get rid of the ln yielding (2y-1)/(y-1) = e^x, but why the heck would you just switch the y's with the e^x after that? Is it because the graph has symmetry over the y=x line? That's all I can figure. If that is the case, how can you tell this is true offhand?

http://www.wolframalpha.com/input/?i=graph+y+=+(e^x-1)/(e^x-2)"

http://www.wolframalpha.com/input/?i=graph+(2y-1)/(y-1)+=+e^x"

Thanks!
 
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so what exactly is the equation? i don't get what you are trying to say. is this about Inverse Function or Logarithm?(log and ln?)
 
The equation is in terms of x, I want it in terms of y. I want y = " ". Wolfram did this for me, but I'm wondering HOW it did it. It switched the y's with the e^x, and it looks like it came out right, what method/identity did it use to achieve this?
 
It's just algebra, multiply both sides by y-1, gather like terms, factor out the y, etc.
 

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