Mastering the Integration of 1/sqrt(x-1): Tips and Tricks

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Trying to do an improper integral but for some reason am flummoxed by the integration of 1/sqrt(x-1).
 
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Have you tried the substitution u^{2} = x-1?
 
nope, thank-you!
 
Why that substitution, I wonder? It seems to me that the substitution u=x+1 would be simpler... but I'm sure that, if I tried yours, it would work out just as easy.

Wait, I did. And it was quite easy. Thanks for the alternative substitution route, I actually like this one better.
 
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╔(σ_σ)╝ said:
Have you tried the substitution u^{2} = x-1?

Char. Limit said:
Why that substitution, I wonder? It seems to me that the substitution u=x+1 would be simpler... but I'm sure that, if I tried yours, it would work out just as easy.

Wait, I did. And it was quite easy. Thanks for the alternative substitution route, I actually like this one better.

Probably a typo, but u = x - 1 is a better choice than u = x + 1.
 
Mark44 said:
Probably a typo, but u = x - 1 is a better choice than u = x + 1.

Indeed. u=x-1 is what I meant.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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