第3个回答 2018-12-24
令 u = x^(1/6), 则 x = u^6
I = ∫√xdx/[1+x^(1/3)] = ∫u^3(6u^5du)/(1+u^2)
= 6∫[(u^8+u^6)-(u^6+u^4)+(u^4+u^2)-(u^2+1)+1]du/(1+u^2)
= 6∫[u^6-u^4+u^2-1+1/(1+u^2)]du
= 6(u^7/7-u^5/5+u^3/3-u+arctanu) + C
= (6/7)x^(7/6)-(6/5)x^(5/6)+2x^(1/2)-6x^(1/6)+6arctanx^(1/6) + C本回答被网友采纳