例7.4.9利用全微分形式不变性解例7.4.1 解：dz=d(e"sinv) e"sinvdu +e"cosvdv =e*[sin(x+y)d(xy)+cos(x+y)d(+y)] e*[sin(x+y)(ydx+xdy)+cos(x+)(dx+dy)] =e*[ysin(x+y)+cos(x+y)]dx +e*[xsin(x+y)+cos(x+y)]dy 所以 Ox =exY[y.sin(x+y)+cos(x+y)] =e*[x.sin(x+y)+cos(x+y)] BEIJING UNIVERSITY OF POSTS AND TELECOMMUNICATIONS PRESS 目录上页下页返回结束目录 上页 下页 返回 结束 例1 . z e sin v, u xy, v x y, u = = = + , . y z x z     求 例7.4.9 利用全微分形式不变性解例7.4.1 解: dz = d( ) e [ y sin(x y) cos(x y)] xy = + + + 所以 v u e sin v v u + e cos d d (xy) d (x + y) (dx + dy) d x dy (yd x + xdy)