arctan(1/x)求导

arctan(1/x)求导
arctan(1/x)求导

arctan(1/x)求导
[arctan(1/x)]'
=1/[1+(1/x)^2]*(1/x)'
=[x^2/(1+x^2)]*(-1/x^2)
=-1/(1+x^2)

[arctan(1/x)]'
={1/[(1/x)^2+1]}(1/x)'
=(x^2)/(x^2+1)(-1)/(x^2)
=-1/(x^2+1)

[arctan(1/x)]' =1/[1+(1/x)^2]*(1/x)' =[x^2/(1+x^2)]*(-1/x^2) =-1/(1+x^2)

复合求导问题，很简单。
-1/(x^2+1)