If a function f(x) is constant complexity f ( x ) = O ( 1...

If a function f(x) is constant complexity $f(x)=O(1)$, describe C and k.
If a function f(x) is constant complexity $f(x)=O(1)$, describe C and k.
This needs to be described in terms of the relation of C and k.
There exists constants C and k such that $C|f(x)|\le |1|$, for all $x>k$.
The above cannot be true because using the explanation from the book of discrete math:
f(x) is O(g(x)) if there are constants C and k such that $\mathrm{\forall }x>k,|f(x)|\le C|g(x)|.$.
So if $f(x)=O(1)$, then it would mean $O(1)\le C|g(x)|$, or $C|g(x)|\ge O(1)$.
Instead the below statement is true.
There exists constants C and k such that $C|f(x)|\ge |1|$ for all $x>k$.