David M. answered 04/30/20
Dave "The Math Whiz"
Because the directrix is of the form x = ? the standard form for this parabola will be x = a(y - k)2 +h. The focus is (2,2) which has to be of the form (h + 1/4a,k). The formula for the directrix is x = h - 1/4a.
Vertex: (h,k) = (2,2)
h = 2 k = 2
Directrix: x = h - 1/4a
-2 = 2 - 1/4a
1/4a = 2 + 2
1/4a = 4
1 = 4(4a)
1 = 16a
a = 1/16
Putting these values for "a", h and k into our standard form, we get:
x = a(y - k)2 + h
x = (1/16)(y - 2)2 + 2
Hope this helps!