1 Answer

given the horizontal 4p(x − h) = (y − k)^2
the vertex is at (h,k)
the focus is at (h+p,k)
the directrix is at x= h−p
and the focal width = 4p
so x = 4y^2
∴ (1/4)(x − 0) = (y − 0)^2
∴ 4(1/16)(x − 0) = (y − 0)^2
so the vertex is at (h,k) = (0,0)
the focus is at (h+p,k) = (1/16,0)
the directrix is x = h−p ⇒ x = 1/16
the focal width is 4p = 1/4
Source(s): http://www.mathwords.com/p/parabola.htm