5. If the directrix is above the vertex, as in this case, this parabola turns downward
So.....p = the distance from the directrix to the vertex = 5
So....we have the form
-4py = x^2
-4(5)y = x^2
-20y = x^2 divide both sides by -20
y = (-1/20)x^2
6) First.. in the form x = ay^2 ...the vertex is at the origin
x = (1/24)y^2 multiply both sides by 24
24x = y^2
We have the form
4px = y^2 so 4p = 24 ⇒ p = 6
This parabola opens to the right so the focus is (0 + p, 0) = (0 + 6 , 0 ) = (6, 0)
The directrix is x = 0 - p ⇒ x = 0 - 6 ⇒ x = -6