How to do this kind of integral?

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Homework Statement


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

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The Attempt at a Solution

 
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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...
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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