From the focus/directrix definition of a hyperbola: If the distance from the focus to a point $(x, y)$ is greater than the distance from the directrix to $(x, y)$
one branch of a hyperbola is formed. Using (2,0) as the focus and the vertical line $x=\frac{1}{2}$ as the directrix, find an equation for the set of all points $(x, y)$ where the distance from the focus to $(x, y),$ is twice the distance from the directrix to $(x, y)$.