please help me with this, i cannot seem to integrate these two...

integrate

dx/ x^4(1+x^2)^(1/2)

using the substitution x = 1/ (u^2-1)^(1/2)

and

x^2(1+x^2)^(1/2) using the substitution x = tan u

p.s.

does anyone know exactly how to write these equations and formulas "properly", with the integral sign and such? I have a program called mathematica but it is not compatible here on the forum.