The root of polynomial $ p(x) $ is:
$$ \begin{aligned}x &= 1 \end{aligned} $$Step 1:
Write polynomial in descending order
$$ \begin{aligned} x^2+1-2x & = 0\\[1 em] x^2-2x+1 & = 0 \end{aligned} $$Step 2:
The solution of $ ~ x^2-2x+1 = 0 ~$ is $~ x = 1 ~$.
You can use step-by-step quadratic equation solver to see a detailed explanation on how to solve this quadratic equation.