z=arctan(xy)偏导数怎么求呢 日期:2011-06-22 15:41:08 人气:1 z=arctan(xy)偏导数怎么求呢 ∂z/∂x=[1/(1+(xy)²)]*y=y/(1+x²y²) ∂z/∂y=[1/(1+(xy)²)]*x=x/(1+x²y²)