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问题: 高等数学提,帮忙啊4

解答:

分部积分法
∫xln(1+x)dx
=1/2×∫ln(1+x)d(x^2)
=1/2×[x^2×ln(1+x)-∫x^2/(1+x)dx]
=1/2×x^2×ln(1+x)-1/2×∫[x-1+1/(1+x)]dx
=1/2×x^2×ln(1+x)-1/2×[1/2×x^2-x+ln(1+x)]+C
=1/2×x^2×ln(1+x)-1/4×x^2+1/2×x-1/2×ln(1+x)+C