z=x*arctan(xy),求(dz/dx)|(1,1),(dz/dy)|(1,1)

z=x*arctan(xy),求(dz/dx)|(1,1),(dz/dy)|(1,1) z=arctan(x/y),求dz 设z=arctan(xy),y=e^x ,求dz/dx ． z=arctan(xy),而y=e^x,求dz/dy 设z=arctan(xy)+2x^2+y^2,求dz z=x^2*arctan(2y/x)求dz z=arctan（x-y）,求dz 全导数:设z=arctan(xy),而y=e*x次方,求dz/dx设z=arctan(xy),而y=e*x次方,求dz/dx, 设z=arctan(xy),y=e的x次方,求dz/dx不是dz/dx=@z/@y *dy/dx吗（@指偏导），为什么直接对z求导呢？那之后的dy/dx怎么求呢？ z=arctan x/(1+y^2),则dz=? 设函数z=arctan(x/y),求全微分dz z=arctan(x+y)/(1-xy)求dz还有个题 f(x,y)=√（x^2+y^2）则dz 这是要求什么啊 不太明白 谢 z=xy,x=siny,求dz/dy 设z=(x+y)^xy,求dz z=f(x/y,xy),求dz z=f(xy,x^y),求dz. 设z=(x+2y)e^xy,求dz Z=arctan(xy) 而y=e的x次方,则dz/dx=?最好说下过程