z=xe^xy,求dz

高数设z=f(e^xy,y/x),求dz 设Z=x²+2xy,求dz z=x*arctan(xy),求(dz/dx)|(1,1),(dz/dy)|(1,1) 设Z=f(x^2 +y,2xy),求dz/dx和dz/dy z=(1+xy)^x就是（1+xy)的x次方 求dz 设函数z=f(x,y)是由方程y^2z=xe^z所确定的隐函数,求dz 设z=u^2cosv^2,u=x+y,v=xy,求dz/dx,dz/dy. 设z=ln(eu+v),v=xy,u=x2-y2,求dz/dx,dz/dy. z= xy ln(xy) 求全微分dz z=f(x,y) xy+yz+xz=1 ,求dz 设z=arctan(xy),y=e的x次方,求dz/dx 求函数z=e^xy*cos(x+y)的全微分dz