Integration by Parts Problem (Natural Log)

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abel216
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Homework Statement


[Intgrl]ln(x^(2)+4)dx

Homework Equations


[Intgrl]udv=uv-[Intgrl]vdu

The Attempt at a Solution


[Intgrl]ln(x^(2)+4)dx, u=ln(x^(2)+4), du=(2x/x^(2)+4), dv=dx, v=x
xln(x^(2)+4)-[Intgrl](2x^(2)/(x^(2)+4))dx
 
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You're almost done. Just write
[tex]\int \frac{2x^2}{x^2 + 4} dx = 2 \int \left( 1 - \frac{1}{1 + \left(\frac{x}{2}\right)^2} \right) dx[/tex]
and substitute [tex]t = \frac{x}{2}[/tex]. (You do know how to integrate [tex]\frac{1}{1 + x^2}[/tex], right?)