Prove or disprove that $n^2-1$ is composite whenever $n$ is a positve integer greater than 2.

Question

I have no idea where to start with this. My initial thought is to use induction as I have plugged in multiple values of $n\gt2$ to see if the values are composite and they are. But I do not know how to show that for every $n\gt2$ the statement is true.

Answer 1

$n^2-1=(n-1)(n+1)$, and since $n > 2$,$n-1\ne1$. Thus, $n^2-1$ is not a prime number and is hence composite.