The possible values of x2+4 lie in the interval
(0,4]
(4,∞)
(0,4)
[4,∞)
We know that x2≥0
⇒x2+4≥4
So, possible values of x2+4 lie in the interval [4,∞) .
The possible values of x2+6 is (x is real)
The domain of definition of f(x)=√4x−x2 is
The possible values of expression 1x2−x−3 is