n_0 in complexity question

[EvLer]

Let's say f(n) = O(g(n)), i.e. f(n) < cg(n) for some n > n_0. Does the n_0 have to be a precise point of intersection of cg(n) and f(n) or just any point for which n > n_0?

Thanks in advance.

[Hurkyl]

Any such point n_0 is fine.