高数,求导数 

首先du/dx=cos(x+y) *d(x+y)/dx=cos(x+y) *(1+dy/dx)而e^y +y=x+sinx,对x求导得到e^y *y' +y'=1+cosx即y'= (1+cosx)/(1+e^y)于是du/dx=cos(x+y) *(1+dy/dx)=cos(x+y) * [1 + (1+cosx)/(1+e^y)]=cos(x+y) *(2+e^y+cosx) / (1+e^y)就是你要的答案