ANote  If we restrict the domain of  f to [– 2, 1] only,
then f will have maximum value(– 2)2 = 4 at x = – 2 Example 15 Find the maximum and minimum values
of  f , if any, of the function given by f(x) = |x|, x ∈ R Solution From the graph of the given function
(Fig 6 9) , note that
f (x) ≥ 0, for all x ∈ R and  f (x) = 0  if  x = 0