Let's start constructing the locus parabola throughout its definition:[br]LOCUS OF POINTS THAT HAVE THE SAME DISTANCE FROM A FIXED POINT CALLED FOCUS AND A LINE CALLED DIRECTRIX[br]You can follow the steps clicking the rows on the bottom of the Geogebra sheet.[br]a) plot a point F and draw a line = the directrix[br]b) put a a point C on the line and draw the perpendicular trough C to it[br]c) draw the axis of FC[br]d) this axis intersects the perpendicular line at a point P, which has the same distance from P and F ( as the axis definition tell)[br]e) move C on the directrix ed we obtain the parabola