If the width of the parabola is 60 and the height is 30,......by letting the vertex lie at the origin, then the point (30, 30) is on the graph..........so we have the follwing function where p is the distance from the vertex to to focal point
y = ( x ) ^2 / [4p] and since the point (30,30) is on the graph,we have
30 = (30)^2 / [4p] divide both sides by 30
1 = 30 / [4p] multiply both sides by 4p
4p = 30 divide both sides by 4
p = 7.5 the focal point is 7.5 units above the vertex = (0, 7.5)
