1) (u*v)' = u'v + v'u
f' = (1 +x^2)'[3 - 1/(x^3)] + (1 +x^2)[3 - 1/(x^3)]' =
= 2x*[3 - 1/(x^3)] + (1 +x^2)*3x^(-4) =
= 6x - 2/(x^2) + 3/x^(4) + 3/(x^2) =
= 3/x^(4) + 1/(x^2) +6x
2) (a^u)' = a^u*lna*u'
f' = 3^[2*(x^2)]*ln3 * (2*x^2)' = 3^[2*(x^2)]*ln3*4x