1974 USAMO Problems/Problem 1
Problem
Let ,
, and
denote three distinct integers, and let
denote a polynomial having all integral coefficients. Show that it is impossible that
,
, and
.
Solution
It suffices to show that if are integers such that
,
, and
, then
.
We note that
so the quanitities
must be equal in absolute value. In fact, two of them, say
and
, must be equal. Then
so
, and
, so
,
, and
are equal, as desired.
Alternate solutions are always welcome. If you have a different, elegant solution to this problem, please add it to this page.
See Also
1974 USAMO (Problems • Resources) | ||
First Question | Followed by Problem 2 | |
1 • 2 • 3 • 4 • 5 | ||
All USAMO Problems and Solutions |