f(x,y)=arctan(y/x),则f(x,kx)=都忘记了,

f(x,y)=arctan(y/x),则f(x,kx)=都忘记了, 已知f(x,y)=x^2arctan(y/x)-y^2arctan(x/y)求它的混合二阶偏导 设y=arctan x,求f'(0),f(0). arctan(x,arctan(x,y)是不是等于arctan(x/y)? arctan(y)=x+1, y=? 设y=arctan(x-y),则dy= 设 y=4 arctan x ,则y'(1)=? arctan(x+y)=x的导数 y=2x*arctan(y/x),求y‘’ f(x,y)=arctan(xy),则fx=(1,1)=? 设F(X,Y)=arctan(x/y),求df|(1,1) f(arctan(y/x))=xy求y对x的一阶导. f(x,y)=arctan(x+y)/(1-xy)怎么求导? y=arctan(1/x)求导 y=arctan（x/2）求导? z=arctan(x/y),求dz y=arctan√x求导 求导 y=(arctan x)^2