e^y+xy-e=0两边对x求导y'e^y+y+xy'=0y'(e^y+x)+y=0y'=-y/(e^y+x)y'(e^y+x)+y=0两边对x求导y''(e^y+x)+y'(y'e^y+1)+y'=0y''(e^y+x)+e^y(y')^2+2y'=0y''=-[e^y(y')^2+2y']/(e^y+x)y''=-[e^y(-y/(e^y+x))^2+2(-y/(e^y+x...