cos(x*x+y*y) ,求dz每一步都要

cos(x*x+y*y) ,求dz每一步都要 z=arctan(x/y),求dz 设z=x^y,求dz 设z=cos²x/y则dz=? z=x^y+y^x求dz/dx z=x^y+y^x 求dz/dx 设z=(x+y)/(x-y),求dz 求函数z=e^xy*cos(x+y)的全微分dz z=x^2*arctan(2y/x)求dz 设z=ln(x^z×y^x),求dz 设函数z=f(x,y)由方程e^z=xyz+cos(xy)求dz/dx ,dz/dy.求详解 z=x^2-y/x+y,而y=2x-3,求dz/dx. 『紧急』 设z=y*cos(x+y),则dz等于什么? 『紧急』 设z=y*cos(x+y),则dz等于什么? 函数z=In(1+x+y),求dz z=arctan（x-y）,求dz 设z=(x+y)^xy,求dz z=3x^3y^2,求dz