Question

Need help with this homework Part 2) construct the line that is perpendicular to the directrix and passes through the focus. This line will be the axis of symmetry of the para bola what are the coordinates of the point of intersection,A, of the access of symmetry and directrix of the parabola

Answer 1

After following the instructions in part A, the result is

In general, the equation of a horizontal line is y=a, with 'a' a constant. In our case, the line has to be 6 units below F; then y=4-6=-2. The equation of the directrix is y=-2

Part 2)

In Geogebra, go to Tools->Construct->Perpendicular Line; then, click on point F and line y=-2. A new line should appear on your screen, then go to Tools->Points->Intersect and select both lines. After naming the intersection point as 'A', the result is

The answer to part 2) is A=(6,-2)