∫ (1,-1)xe^(x|x|)dx
问题描述：
∫ (1,-1)xe^(x|x|)dx
答
∫(-1,1)xe^(x|x|)dx
=∫(-1,0)xe^(-x^2)dx+∫(0,1)xe^x^2dx
=-1/2∫(-1,0)e^(-x^2)d(-x^2)+1/2∫(0,1)e^x^2dx^2
=1/2e^(-x^2)|[-1,0]+1/2e^x^2|[0,1]
=1/2[1-e^-1]+1/2[e-1]
=1/2[e-(1/e)]