设u=ln(x+y^2+z^3),求du一道偏导全微分的题,
问题描述:
设u=ln(x+y^2+z^3),求du
一道偏导全微分的题,
答
u'x=1/(x+y^2+z^3)
u'y=2y/(x+y^2+z^3)
u'z=3z^2/(x+y^2+z^3)
du=u'xdx+u'ydy+u'zdz
=1/(x+y^2+z^3)dx+2y/(x+y^2+z^3)dy+3z^2/(x+y^2+z^3)dz