Question

Integrating (-2x)/(x^4 + 1) dx.

Could someone please help me do this one?

Answer 1

try \(u=x^2\) and get a familiar anti derivative, namely \(\tan^{-1}(u)\)

Answer 2

\[u=x^2, du=2xdx,=du=2xdx\] gives you
\[-\int\frac{du}{1+u^2}\]

Answer 3

typo there, i meant \(-du=2xdx\) but the idea is right

Answer 4

Oh, man! That was easy!

Answer 5

yup

Answer 6

Thanks! :D

Answer 7

yw