Answer:
4 m
Step-by-step explanation:
The equation can be written ...
y = (x/4)² = (1/16)x²
where the divisor 4 is the horizontal scale factor that makes the parabola 8 m wide at y = 1 m.
This can also be written as ...
y = 1/(4p)x² = (1/16)x²
from which we can see ...
4p = 16
p = 4
In this form, p is the distance from the vertex to the focus, 4 meters.
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Another way to find the y-coordinate of the focus is to draw a line with slope 1/2 through the vertex. It will intersect the parabola at the point where the vertical distance to the directrix is the same as the horizontal distance to the focus. The y-coordinate of that point is the y-coordinate of the focus.
