简单计算一下即可,答案如图所示
如图
∫xln(x+1)dx=∫ln(x+1)d(1/2*x^2)=1/2×x^2×ln(x+1)-1/2×∫x^2dln(x+1)=1/2×x^2×ln(x+1)-1/2×∫x^2/(x+1)dx=1/2×x^2×ln(x+1)-1/2×∫[x-1+1/(x+1)]dx=1/2×x^2×ln(x+1)-1/2×[1/2×x^2-x+ln(x+1)]+C=1/2×(x^2-1)×ln(x+1)-1/4×(x^2-2x)+C代入结果为1/4.