Answer
$y'=1-\csc^2(x)$.
Work Step by Step
$y=g(x)+h(x)\rightarrow g(x)=x$ and $h(x)=\cot(x)$.
Using the Power Rule: $g'(x)=1$.
By Theorem $2.9$: $h'(x)=\frac{d}{dx}(\cot(x))=-\csc^2(x)$.
Using the Sum Rule $y'=g'(x)+h'(x)$.
$y'=1-\csc^2(x)$.