∫[xsinx/(1+e^x)]dx=∫[xsinx/(1+e^x)]dx+∫[xsinx/(1+e^x)]dx (分成两个积分)=-∫[xsinx/(1+1/e^x)]dx+∫[xsinx/(1+e^x)]dx (第一个积分用-x代换x)=∫[xsinx/(1+1/e^x)]dx+∫[xsinx/(1+e^x)]dx =∫[1/(1+1/e^x)+1/...