LOCUS PARABOLA
YOU are going to create the graph of a parabola by its definition:
THE LOCUS OF THE POINTS SUCH THAT THE DISTANCE FROM A GIVEN POINT (FOCUS) IS EQUAL TO THE DISTANCE FROM A GIVEN STRAIGHT LINE (DIRECTRIX).
a) plot a point F and a straight line d wherever you want
b)put on d a point C and trace the perpendicular line to d through C
c) trace the segment's axis of FC
d) the axis intersect the perpendicular line at the point called P (activate TRACE for the point P); P because of the axis' definition has the same distance from C and F.
e) move C on the directrix and you'll get the locus Parabola.