Hence
x = 1 is the only point of discontinuity of f The graph of the function is given in Fig 5 4 Example 11 Find all the points of discontinuity of the function f defined by
f (x) = 
2, if
1
0,
if
1
2, if
1
x
x
x
x
x
+
<

=

 −
>

Solution As in the previous example we find that f
is continuous at all real numbers x ≠ 1