I have this integral:
$\int{\frac{x}{1+x^4}\ dx}$
The solution should be:
$\frac{1}{2} \arctan{x^2}+C$
But I have only seen how to integrate when in denominator I have an expression with real roots. Here, with $1+x^4$ I dont have any real roots and I don't know how I can integrate it.