z=sin(x,y)求Z在(1,1)点对X的偏导数

问题描述:

z=sin(x,y)求Z在(1,1)点对X的偏导数

sin(x,当做sin(x×y)做吧!
Z′x=ycos(xy).Z′x|(1,1)=cosi
Z′y=xycos(xy).Z′y|(1,1)=cosi