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An Integral problem with x,lnx with progress done [ check it]

  • Thread starter Riazy
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An Integral problem with x,lnx with progress done [plz check it]

QUESTION: How and what was changed from the original formula?
Whats up with all the Sqrts above the 5:s
Is this some kind of compensation because the current formula
diverge from the Real formula? How was it done?


Homework Statement


$dx/x(5*(lnx)^2), See a detailed scanned paper below


Homework Equations



You can find everything on the scanned paper below

The Attempt at a Solution



Yes The problem is solved already, but I have questions on why certain things are like they are. See the scanned paper. Thanks

Scanned Solution [PLAIN]http://img146.imageshack.us/img146/3544/kaat001.jpg [Broken]
 
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Answers and Replies

  • #2
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The formula says that when the denominator is a2 + x2, the resulting expression uses a. The original expression has [itex]5 + u^2 = (\sqrt{5})^2 + u^2[/itex] in the denominator, so the resulting expression uses [itex]\sqrt{5}[/itex].
 

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