The vertex form of a parabola that opens to the right (or left) is x = a (y-k)^2 + h , where
(h,k) is the vertex
y^2 - 8x - 4 = 0
y^2 = 8x - 4
(y-0)^2 = 8(x - 1/2)
1/8 (y-0)^2 = x - 1/2
x= 1/8 (y-0)^2 + 1/2
Therefore, the vertex of the parabola is at (1/2, 0).
Note: If the parabola opens upward or downward, the vertex form would look like:
y = a (x-h)^2 + k , where (h,k) is the vertex