Question 768170
Briefly, you can use the definition of a parabola.  The directrix is on the other side of the vertex than the focus.  From  -6.125, to -6.000, to -5.875, The directrix would be {{{y=-5.875}}}, or {{{y=-5&7/8}}}.


You use the distance formula, the focus, and the directrix, to find the set of points equally distant from the focus and the directrix.