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

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The discussion revolves around solving the equation ln((2y-1)/(y-1)) = x for y. The initial step involves exponentiating to eliminate the natural logarithm, resulting in (2y-1)/(y-1) = e^x. The confusion arises regarding the manipulation that appears to switch y and e^x, which is clarified as a standard algebraic process rather than a direct switch. The solution involves rearranging the equation, multiplying by (y-1), and factoring to isolate y. Ultimately, the method used is algebraic manipulation, not a reflection of symmetry or inverse functions.
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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.
 
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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