Create slide D with boundaries of -10 to 10
Create line D by typing in input bar x=D
Have D show its name and value and rename it Directrix.
Create a Point called F
Have F show its name and value.
Create Parabola by using parabola tool
Create h by typing in the input bar h=(x(F) - D) / 2 + D
Create k by typing k=y(F)
Create Vertex by V=(h,k) and rename it Vertex and have it show name and value.
Create p by typing p=(x(F) - h)
Create a text box and type x=4*p (y-h )²+k, p, h, & k are objects you have to select them from the object menu.
Fix the text box and the slider bar.
