1. Zn

I have to find the polynomial over Zn with degree 2, which has at least three roots in Zn.
Can you give me a hint please?
THANK YOU!!

2. Originally Posted by sidi

I have to find the polynomial over Zn with degree 2, which has at least three roots in Zn.
Can you give me a hint please?
THANK YOU!!
are you looking for just an example (very easy! choose $n = 16$ and $f(x) = x^2$) or some sort of characterization (not very easy!)?