I can't seem to get the correct answer for this:
Find the indefinite integral by using the substitution x = tan().
integral x^2/(1+x^2)^2 dx
Thanks
tan(t) = x
sec(t)^2 dt = dx
tan(t)^2 * sec(t)^2 dt/(1+tan(t)^2)^2
tan(t)^2 * sec(t)^2 dt/(sec(t)^2)^2
tan(t)^2 dt /sec(t)^2
sin(t)^2 dt
Integrate this using trigo identities on wikipedia.