设z=arctan(xy)+2x^2+y^2,求dz

设Z=f(x^2 +y,2xy),求dz/dx和dz/dy 设z=arctan(xy),y=e的x次方,求dz/dx 设Z=x²+2xy,求dz 设z=u^2cosv^2,u=x+y,v=xy,求dz/dx,dz/dy. 设z=z(x,y)是由方程e^(-xy)+2z-e^z=2确定 求dz|(x=2,y=-1/2) 设x+y^2+z=ln(x+y^2+z)^1/2,求dz/dx 设z=z（x,y）由e^（-xy）-2z+e^z=0所确定的二元函数 求dz 高数题,设z=x^2+xy+y^2,则dz= z=x*arctan(xy),求(dz/dx)|(1,1),(dz/dy)|(1,1) 设二元函数 z=u^2,u=x+y v=x-y ,求dz/dx,dz/dy z=f(x,2x+y,xy),f有一阶连续偏导数,求dz 设函数z=(x,y)由方程x^2+z^2=2ye^z所确定,求dz