How to do this kind of integral?

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SUMMARY

The integral \(\int_0^{\infty}\frac{xdx}{1+x^4}\) can be evaluated using residue calculus by employing a contour integration technique. The solution involves using a quarter-arc contour that traverses the upper half-plane, followed by integration along the y-axis and the x-axis. This method effectively circumvents the issue of the function being odd, which would otherwise result in a zero value when evaluated over the entire real line.

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Homework Statement


I want to evaluate, using residue calculus, the following
[tex]\int_0^{\infty}\frac{xdx}{1+x^4}[/tex]
I can't find any kind of formula for this kind of integral though. We just know [tex]\int_{-\infty}^{\infty}\frac{P(x)dx}{Q(x)}[/tex], however that would give 0 in this case as the function is odd. Any pointers?

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The Attempt at a Solution

 
Last edited:
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Err... figured it out. Just have to use a the contour with a quarter-arc, then along the y-axis, then the x-axis...
 

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