x=y+arctany 求隐函数的导数dy/dx.
问题描述：
x=y+arctany 求隐函数的导数dy/dx.
答
y+arctany-x=0
dy/dx+1/(1+y^2)dy/dx-1=0
dy/dx(1+1/(1+y^2)=1
dy/dx=(1+y^2)/(2+y^2)