Putnam problems e 3 diagonais

["Luis Lopes" <llopes@xxxxxxxxxxxxx>]

Sauda, co~es,

Aih vai a resposta do prof. Rousseau.

Ele também comenta no problema das diagonais que se
encontram fora do centro no polígono com 2n vértices.

[ ]'s
Luís

===
Dear Luis:

    There are two books of Putnam problems, both published by the
Mathematical Association of America.   The first book is by Greenwood,
Gleason and Kelly and covers 1938-1964.  The solutions are mostly
"original" ones by the authors.  The second book is edited by Alexanderson,
Klosinksi, and Larson, and mostly consists of reprinted versions of ones
that previously appeared in the American Mathematical Monthly.

When you say diagonal, do you mean any chord?  It would seem that
for a 2n-gon with at least n at least 4 the chords (a-1,a+2), (a-2,a+1)
and (a, a+n) are three chords that intersect at a point other than the
center.  (Number the vertices 1,2,...2n, count modulo 2n and let a
be any vertex.)  This obviously generalizes, but  I don't know off hand
about three concurrent chords, none of which passes through the
center.

Cecil
===

-----Mensagem Original-----
De: Luiz Ozorio <ozorio@if.usp.br>
Para: <obm-l@mat.puc-rio.br>
Enviada em: Terça-feira, 5 de Setembro de 2000 14:08
Assunto: Putnam problems


Onde posso encontrar as soluções para os problemas do Putnam problems.
Existe algum livro com a compilação dos problemas e suas soluções? Se
existe onde posso comprá-lo?