The vertex form of the equation of a vertical parabola is given by , where (h, k) is the vertex of the parabola and the absolute value of p is the distance from the vertex to the focus, which is also the distance from the vertex to the directrix. you will use the geogebra geometry tool to create a vertical parabola and write the vertex form of its equation. open geogebra, and complete each step below. if you need , follow these instructions for using geogebra. part a mark the focus of the parabola you are going to create at f(6, 4). draw a horizontal line that is 6 units below the focus. this line will be the directrix of your parabola. what is the equation of the line?