Show that for all integers n>2, n does not divide n^2+2

  • Thread starter Thread starter numba
  • Start date Start date
  • Tags Tags
    Integers
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
3 replies · 3K views
numba
Messages
2
Reaction score
0

Homework Statement


Show that for all integers n>2, n does not divide n^2+2.

2. The attempt at a solution
I believe this solution can be solved by induction, I just don't know how to phrase it recursively.

For all n>2, n^2+2 mod n ≠ 0

Base case n=3
3^2 + 2 =11
11 mod 3 = 2 ≠ 0.

Show that
(n-1)^2 +2 mod n-1 ≠ 0
 
Physics news on Phys.org
I can use that, but I'm not sure how it would be done. Intuitively it makes sense, but is there an axiom that I could use that proves this?