∫e^xcosxdx=∫e^xdsinx=e^xsinx-∫sinxe^xdx=e^xsinx+∫e^xdcosx=e^xsinx+e^xcosx-∫e^xcosxdx2∫e^xcosxdx=e^xsinx+e^xcosx∫e^xcosxdx=(1/2)e^x(sinx+cosx)∫[π/2,0] e^xcosxdx= (1/2)-(1/2)e^(π/2)