Solution
= Solution
The evaluated position <vectors> are $\boldsymbol r_1(1)=(2,1,0)$ and $\boldsymbol r_2(-1)=(-1,-1,0)$. Their difference is $(3,2,0)$, so the <Euclidean distance> is
$$
\boxed{\|\boldsymbol r_1(1)-\boldsymbol r_2(-1)\|=\sqrt{3^2+2^2}=\sqrt{13}.}
$$