Question 1171330
<br>
The vertex form of the equation of a parabola is<br>
{{{y = (1/(4p))(x-h)^2+k}}}<br>
where (h,k) is the vertex and p is the directed distance from the vertex to the focus.<br>
We can (arbitrarily) use the foot of the pole as the origin of our coordinate system; then the vertex is at (0,4).<br>
The receiver is at the focus; it is at (0,7), so p, the distance from the vertex to the focus, is 3.<br>
Then the equation is<br>
{{{y = (1/12)x^2+4}}}<br>