设z=arctan[（x+y）/（x-y）],则dz=?

设z=arctan[（x+y）/（x-y）],则dz=? 设函数z=arctan(x/y),求全微分dz 设z=arctan(x+y),则σz/σy=? z=arctan(x/y),求dz arctan(x-y)^z求偏导 z=arctan（x-y）,求dz z=arctan(x+y)/(x-y)的全微分 z=arctan(y/x) x,y的偏导数 设函数z=(x^2+y^2)*{e^-arctan(x/y)},求dz与a^2z/axay 求函数偏导：z=arctan(x-y)^z 设z=arctan(xy),y=e^x ,求dz/dx ． 设z=arctan(xy)+2x^2+y^2,求dz z=x^2*arctan(2y/x)求dz 设u=arctan(x+yz),则∂^3z/∂x∂y∂z= 设u=arctan(x+yz),则∂^3z/∂x∂y∂z= 设Z=arctan(y/x)的点m（1,1）处的全微分dz(1,1)为? 设y=arctan(x-y),则dy= 设 y=4 arctan x ,则y'(1)=? z=arctan x/(1+y^2),则dz=?