z=3x^3y^2,求dz

z=3x^3y^2,求dz z=(e^3y) +(x^2)Xsiny,求dz z=(2y+7)^2 * ln(x^3+2) 求dz/dx 和 dz/dy 若z=e^（x^2+y^3）,求dz/dx,dz/dy同上 z=x^2-y/x+y,而y=2x-3,求dz/dx. z=x^2-xy+y^3 求全微分dz 设有方程x+y^2+z^2=2z,求dz/dx dz/dy 设z=f(2x+3y,e^xy),求dz z=x^2*arctan(2y/x)求dz z=arctan(x/y),求dz 设z=x^y,求dz 设函数z=x^3y-2x^y^3,分别求dz/dx和dz/dy在（1,1）处的值 z=ln(x^2+y^2),求dz, Z=（x^2+y^2）求dz 设z=(x+2y)e^xy,求dz z=ln(X平方+Y平方+2),求Dz? 设函数Z=y^(2x) ,求dz . 函数z=f(x,y)由方程2sin(x+2y-3z)=x+2y-3z所确定,求dz