1.求下列复合函数的偏导数或导数:-|||-(1)设 =arctan (xy) ,y=e^x, 求 dfrac (dx)(dx)-|||-(2)设 =dfrac ({x)^2+(y)^2}(xy)(e)^dfrac ({x^2+{y)^2}(xy)} 求 dfrac (partial z)(partial x), az/ay;-|||-(3)设 =(x)^2+xy+(y)^2 =(t)^2 ,y=t, 求 dfrac (dz)(dt);-|||-(4)设 =(x)^2ln y =dfrac (u)(v), =3u-2v, 求 dfrac (partial z)(partial u) ,az/gv;-|||-(5)设 =f(x+y,xy), 求 dfrac (partial u)(partial x), dfrac (partial u)(partial y);-|||-(6)设 =f(dfrac (x)(y),dfrac (y)(z)), 求 dfrac (partial u)(partial x), dfrac (partial u)(partial y) ,an/b^2-