解答题 14.求u=xyzx+y+z的全微分.
【正确答案】ux'=(1+x)yzex+y+z,uy'=(1+y)xzex+y+z,uz'=(1+z)xyex+y+z,du=ex+y+z[(1+x)yzdx+(1+y)xzdy+(1+z)xydz].
【答案解析】