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Integrate the following:

$ \int\cfrac{2}{x^2+4x+13}dx $

$2\arctan {\cfrac{x+2}{3}} +C$

$\cfrac{2}{3}\arctan {\cfrac{x+2}{3}} +C$

$\cfrac{2}{3}\arctan { \left(\cfrac{ ( x+2 ) ^{ 2 }}{3} \right) } +C$

$2\ln {\cfrac{x+2}{3}} +C$