原式=∫e^2x-1/(e^x+1)e^x\de^x =∫(e^x-1)(e^x+1)/(e^x+1)e^x\de^x =∫(e^x-1)/e^x\de^x =∫[1-1/e^x]\de^x =e^x-∫(1/e^x)\de^x =e^x-x 想复杂了 原式=∫e^2x-1/(e^x+1)\dx =∫(e^x-1)(e^x+1)/(e^x+1)\dx =∫(e^x-1)\dx =e^x-x