Write the equation for a paraloba with a focus at (7,2) and a directrix at y=-2

y = (x-7)^2  / 8

Step-by-step explanation:

The focus to vertex distance is (2-(-2))/2 = 2 and the parabola open's upwards.

Thus: a = 1/(4·2) = 8, vertex at (7,0).

This means that:

y = (x-7)2/8

both equations and proportions are better.