求不定积分x⼀(根号x-1)dx

2024-11-19 20:36:03
推荐回答(2个)
回答1:

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

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回答2:

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