Question

Z=ln(y/x)怎么求偏导数求z=x^(xy)的偏导数

Answer 1

z'x=(-y/x^2)/(y/x)=-1/x

z'y=(1/x)/(y/x)=1/y

dz=z'xdx +z'ydy

u=ln(x^2+y^2+z^2)

u'x=2x/(x^2+y^2+z^2)

u'y=2y/(x^2+y^2+z^2)

u'z=2z/(x^2+y^2+z^2)

du=2x/(x^2+y^2+z^2) dx + 2y/(x^2+y^2+z^2) dy + 2z/(x^2+y^2+z^2) dz