Also
f (x) ≥ 0, for all x ∈ R Therefore, the minimum value of  f  is 0 and the point of
minimum value of f is x = 0 Further, it may be observed
from the graph of the function that f  has no maximum value
and hence no point of maximum value of  f  in R ANote  If we restrict the domain of  f to [– 2, 1] only,
then f will have maximum value(– 2)2 = 4 at x = – 2