For this question, let
f ( x ) = 1 − ( 1 + x ) − 1 {\displaystyle f(x)=1-(1+x)^{-1}}
You may use the following facts without proving them:
(a) Give an equation of the tangent line to y = f ( x ) {\displaystyle y=f(x)} at the point ( 10 , 10 11 ) {\displaystyle \left(10,{\frac {10}{11}}\right)} .