Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Help With tricky math word problem?
A satellite is shaped like a paraboloid of revolution. the Signals that emanate from the satellite strike the surface of the dish and are reflected to a single point, where the receiver is located. if the dish is 14 feet across the opening and 4 feet deep at its center, at what position should the receiver be placed
1 Answer
- scott8148Lv 78 years ago
the vertex of the parabola is (0,-4) and the roots (zeros) are plus and minus 7
a(x^2 - 49) = 0
y = a(x - 0)^2 - 4
ax^2 - 49a = ax^2 - 4 ___ a = 4/49
the focal length (distance from vertex to focus) is ___ 1 / 4a
___ in this case ___ 49 / 16
so the receiver should be in the middle of the opening
___ 49/16 feet from the bottom ___ 3 feet 3/4 inch