Can the Integral of 1/(x^5+5) be Evaluated Analytically?

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Homework Statement


Evaluate the integral.


Homework Equations


\displaystyle\int \frac{1}{x^5 + 5} dx


The Attempt at a Solution



could i turn this into an x^2 + a^2 --> arctan

for example: \frac{1}{x^(5/2)^2 + \sqrt{5}^2} dx

note that is: x^{5/2} squared.
 
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Your thread title says, "Is this a trig interval?" :confused:

whatlifeforme said:

Homework Statement


Evaluate the integral.


Homework Equations


\displaystyle\int \frac{1}{x^5 + 5} dx


The Attempt at a Solution



could i turn this into an x^2 + a^2 --> arctan

for example: \frac{1}{x^(5/2)^2 + 5} dx
No. If you let u = x5/2, what would du equal, and can you make the substitution work?
 
how would i solve this then?
 
Wolframalpha gives a very complicated answer, so I'm not sure this integral can be evaluated using the usual analytic methods. Maybe you copied the problem wrong?
 
eumyang said:
Wolframalpha gives a very complicated answer, so I'm not sure this integral can be evaluated using the usual analytic methods. Maybe you copied the problem wrong?

One analytic way to do it is to factor x^5+5 completely over the complex numbers and then use partial fractions. Then carefully track how the complex parts cancel. It's a MASSIVE pain in the neck. I could start it but I would probably never finish. Certainly wouldn't assign it as a problem.
 
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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