How to deal w/ inverse trig function within ∫(x)/((x^2-4)(√(x^4 -8)))?

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SUMMARY

The integral \(\int \frac{x}{(x^2 - 4) \sqrt{x^4 - 8x^2}} \, dx\) can be evaluated using the substitution \(u = x^2\). This leads to the transformation of the integral into \(\frac{1}{2} \int \frac{1}{u \sqrt{x^4 - 8x^2}} \, du\). The discussion highlights the need to handle the term \(\frac{1}{|x| \sqrt{x^2 - 8}}\) and its relationship to inverse trigonometric functions, specifically \(\frac{dy}{d\sec^{-1}(x)} = \frac{1}{|x| \sqrt{x^2 - 1}}\). The key to solving the integral lies in completing the square within the radical and rewriting all terms in terms of \(u\).

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Evaluate the integral \int \frac{x}{(x^2 - 4) \sqrt{x^4 - 8x^2}} \, dx

by making the substitution u = x^{2}

Homework Equations

The Attempt at a Solution

u = x^{2} - 4 so \frac{du}{2}= xdx

\int \frac{1}{(x^2 - 4) \sqrt{x^4 - 8x^2}} \, xdx\frac{1}{2} \int \frac{1}{(u) \sqrt{x^4 - 8x^2}} \, du\frac{1}{2} \int \frac{1}{(u)} \frac{1}{\sqrt{x^4 - 8x^2}} \, du

\frac{1}{2} \int \frac{1}{(u)} \frac{1}{|x|\sqrt{x^2 - 8}} \, duI haven't yet committed all of the inverse trig functions to memory but I have a table that shows dy/dsec^{-1}(x) = \frac{1}{|x| \sqrt{x^2 - 1}}

However, I do not know how to handle \frac{1}{|x| \sqrt{x^2 - 8}}

What does that equal and why? I mean what is the relationship between it and whatever it's antiderivative may be?
 
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Try doing it in two steps. Use the hint and make the first substitution u=x2. Rewrite everything in terms of u. Then complete the square inside the radical and go from there.
 

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