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∫xln(x-1)用分部积分法---

题目详情
∫xln(x-1)用分部积分法---
▼优质解答
答案和解析
∫xln(x-1)dx=(x^2)ln(x-1)-∫xdxln(x-1)
=(x^2)ln(x-1)-∫[xln(x-1)+(x^2)/(x-1)]dx
=(x^2)ln(x-1)-∫xln(x-1)dx-∫(x^2-1+1)/(x-1)dx
2∫xln(x-1)dx=(x^2)ln(x-1)-∫(x^2-1+1)/(x-1)dx
=(x^2)ln(x-1)-∫[x+1+1/(x-1)]dx=(x^2)ln(x-1)-1/2x^2-x-ln(x-1)+C
∫xln(x-1)dx=1/2(x^2-1)ln(x-1)-1/4x^2-1/2x+C