设2x+1为u,du=2xdx
∫x/2x+1 dx
= ∫x/u dx
=∫(2x/2)/u dx
=∫1/2(du/u)
=1/2∫du/u
=1/2 ln lul + C
=1/2 ln l2x+1l + C
够详细了吧.这个题似乎没难度阿,我这个小白都略解一二 .