A Geostationary Earth Orbit is situated directly above the equator and has a period equal to the Earth's rotational period. It is at the precise distance of miles above the Earth that a satellite can maintain an orbit with a period of rotation around the Earth exactly equal to hours. Because the satellites revolve at the same rotational speed of the Earth, they appear stationary from the Earth surface. That is why most station antennas (satellite dishes) do not need to move once they have been properly aimed at a target satellite in the sky. In an international project, a total of ten stations were equally spaced on this orbit (at the precise distance of miles above the equator). Given that the radius of the Earth is miles, find the exact straight distance between two neighboring stations. Write your answer in the form , where are integers and is square-free.
Solution
Let and be two neighboring stations. We have , hence , where . We will prove that .

Since , then . We have:
We may divide by and we get
Denote . Then, our equation becomes
with the solutions given by . Since , then , so that
Now, . It follows

Want a route through all this instead of an archive? The track
puts 2,000 problems in a working order, from AMC 10 level to the IMO shortlist.