i doesn't belong to QQbar ? Why ?
I do not understand this :
sage: sqrt(1) in QQbar
True
sage: sqrt(-2) in QQbar
True
sage: sqrt(-1) in QQbar
False
Can someone explain ?
Note that, however :
sage: [t[0] in QQbar for t in (x^2+1).roots(ring=QQbar)]
[True, True]