0

USAMO 1984:

"$P(x)$ is a polynomial of degree $3n$ such that

$P(0)=P(3)=\cdots =P(3n)=2$

$P(1)=P(4)=\cdots =P(3n-2)=1$

$P(2)=P(5)=\cdots =P(3n-1)=0$

$P(3n+1)=730.$

Determine $n$."

EDIT

This question already exists on the site, but the only answer given used the method of 'Lagrange interpolation', which I have not seen before. I'm fairly sure this problem should have a more elementary proof without using such a method. Instead, I've found this proof (https://mks.mff.cuni.cz/kalva/usa/usoln/usol845.html), which I don't really understand either. If someone could explain it to me that would be much appreciated.

0 Answers0