Thread: Integration

Hi there,

just wondering if someone could help with this: integrate x^3(1+x^8)^-1(dx)

if u=(x^4)^2

how does the x^3 become 1 in this equation?

can you finish?

Thank you skeeter! Yes, I understand not that x^3 gets replaced by 4x^3dx (please correct me if that is not the correct explanation), and does (u^2)^-1 become just u (later on) because tan^-1 multiplies and flips it somehow? Not sure I have that right...