不定积分∫1⼀(a눀+u눀)눀du下述这种解法是怎么算的

2025-06-22 17:39:06
推荐回答(1个)
回答1:

∫ 1/[(1+x^1/3)x^1/2] dx
令x^1/6=u,则x^1/2=u^3,x^1/3=u^2,x=u^6,dx=6u^5du
=∫ 6u^5/[(1+u^2)u^3] du
=6∫ u^2/(1+u^2) du
=6∫ (u^2+1-1)/(1+u^2) du
=6∫ (u^2+1)/(1+u^2) du - 6∫ 1/(1+u^2) du
=6u - 6arctanu + C
=6x^(1/6) - 6arctan[x^(1/6)] + C