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Topic: ---- --- --- --- validity of an equation
Replies: 5   Last Post: Mar 14, 2013 6:20 PM

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Deep Deb

Posts: 390
Registered: 12/6/04
Re: ---- --- --- --- validity of an equation
Posted: Mar 2, 2013 4:45 PM
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On Saturday, March 2, 2013 3:08:24 PM UTC-5, quasi wrote:
> You removed the relevant context, so I'll remove still
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> more.
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> In the reply you snipped, I showed:
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> If x,y,z are integers such that
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> y^(1/2) = (x^10 - z^5)^(1/5)
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> then, letting w = x^10 - z^5, the equation reduces to
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> y^5 = w^2
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> which implies y is a perfect square and w is a perfect 5'th
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> power.
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> Now you ask, what if we assume that y is not a perfect square?
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> Then you get a contradiction, of course.
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> A triviality.
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> quasi


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Thanks quasi, you are right

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