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求∫√(x-1)/xdx

题目详情
求∫√(x-1)/xdx
▼优质解答
答案和解析
令√(x-1)=u,则x=u^2+1,dx=2udu
原式=∫ u/(u^2+1)*2udu
=2∫ u^2/(u^2+1)du
=2∫ (u^2+1-1)/(u^2+1)du
=2∫ 1du-2∫ 1/(u^2+1)du
=2u-2arctanu+C
=2√(x-1)-2arctan√(x-1)+C
数学软件验证,结果正确.
> int((x-1)^(1/2)/x,'x');
2*(x-1)^(1/2)-2*arctan((x-1)^(1/2))