设f(x,y)=sin(xy),则fx(x,y)=?
问题描述：
设f(x,y)=sin(xy),则fx(x,y)=?
答
f(x,y)=sin(xy),则
fx(x,y)=cos(xy) * y
答
应该是对x求偏导,即fx(x,y)=d[f(x,y)]/dx=y*cos(xy)