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Topic: regular n-gon runners problem
Replies: 12   Last Post: Jul 25, 2013 4:26 AM

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 quasi Posts: 12,067 Registered: 7/15/05
Re: regular n-gon runners problem
Posted: Jul 23, 2013 4:28 AM

William Elliot wrote:
>quasi wrote:
>>
>> Suppose n runners, n >= 3, start at the same time and
>> place on a circular track, and proceed to run
>> counterclockwise along the track (forever), each at a
>> distinct positive constant speed.
>>
>> Conjecture:
>>
>> If there is an instant where the locations of the n runners
>> are the vertices of a regular n-gon, then the speeds of the
>> runners, arranged in ascending order, form an arithmetic
>> sequence.

>
>r1 <= r2 <=..<= r_n

The speeds were specified as distinct, so the inequalities are
strict.

>For j = 1,.. n, dj = rj.t, t = dj/rj, dj = j.d1
>
>rj/dj = r1/d1; rj = r1.dj/d1 = j.r1

I have no idea what you are trying to say above.

quasi

Date Subject Author
7/23/13 quasi
7/23/13 Virgil
7/23/13 quasi
7/23/13 quasi
7/23/13 quasi
7/23/13 quasi
7/25/13 quasi
7/23/13 William Elliot
7/23/13 quasi
7/23/13 William Elliot
7/23/13 quasi
7/23/13 James Waldby
7/23/13 quasi