令根号x-1=t
x=t²+1
dx=2tdt
原式=∫ (t²+1)/t · 2tdt
=2∫(t²+1)dt
=2/3t³+2t+c
=2/3 (根号x-1)³+2(根号x-1)+c
|
|
|
-===+=====_/(T)\_=====+===-
| |/.\| |
`-|\_/|-'
解:令 √x-1=t 则x=(t+1)² dx=2(t+1)dt
∫x/(√x-1)dx=∫(t+1)²/t*2(t+1)dt
=2∫(t³+3t+3+1/t)dt
=2t³/3+3t² +6t+2lnt+C