∫1/(x(1+x^2))dx
= ∫ (1/x - x/(1+x^2) ) dx
=ln|x| -(1/2) ∫ dln(1+x^2)
=ln|x| -(1/2) ln(1+x^2) + C
1/[x*(1+x^2)]的不定积分怎么求
∫1/(x(1+x^2))dx
= ∫ (1/x - x/(1+x^2) ) dx
=ln|x| -(1/2) ∫ dln(1+x^2)
=ln|x| -(1/2) ln(1+x^2) + C