Take a sheet of grid paper and draw a straight line in any direction from the origin. What is the closest non-zero grid point $\boldsymbol{p}\in\mathbb{Z}^2$ within a distance $\epsilon>0$ of the line? I have been unable to construct an example where the distance is large for any $\epsilon$. I would like to prove the following: $\forall \epsilon>0 ~~ \exists R>0 ~~ \forall \boldsymbol{v} \in \mathbb{R}^2 ~~ \exists\boldsymbol{q}\in\mathbb{Z}^2, \|\boldsymbol{q}\| < R$ such that: $\frac{|p_x v_y - p_y v_x|}{\|\boldsymbol{v}\|}<\epsilon$ where the LHS is the point-line distance.