I recently came across this question:
Find the number of elements in the following cyclic group:
The cyclic sub-group of $C^{*}$ generated by 1+i
The solution says the answer is: O(Z), where Z is the set of all natural numbers. It further says this is so because $|1+i|=\sqrt{2} >1$.
I couldn't get it intuitively. Why does the order have to be O(Z)?
Can anyone please help?
Thanks in advance!