Question 433509
picture the parabolic cross-section starting at the origin and extending along the x-axis


the vertex (bottom of the dish) is (6,-4); and the roots are 0 and 12


using the vertex form ___ y = a(x - 6) - 4


0 = a(0 - 6)^2 - 4


4 = 36a ___ a = 1/9


a = 1 / 4p ___where p is the distance from the vertex to the focus


p = 1 / 4a ___ in this case ___ p = 9/4


so the receiver is 9/4 feet above the bottom of the dish