Question

more integration: (hopefully the last one)-
(x^3)/(1+x^4)

Answer 1

(1+x^4) = u
du/4=x^3dx

Answer 2

Take u=1+x^4, du=4(x^3)dx
I think we can easily solve, yes?

Answer 3

grrr I can never tell which method to use...I have all these tools in my tool box but can never figure out with one to use.

thanks