y=cos(2x+3)+e^(-5x)求导
dy/dx=-2sin(2x+3)-5e^(-5x),dy=[-2sin(2x+3)-5e^(-5x)]dx.
你作的很正确!再请问下：不定积分e^(3x+1)dx∫e^(3x+1)dx=(1/3)∫e^(3x+1)d(3x+1)=(1/3)e^(3x+1)+C.