The given function f is 
The given function f is defined at all the points of the real line. Let c be a point on the real line.
Case I:
Therefore, f is continuous at all points x, such that x < −3 Case II:
Therefore, f is continuous at x = −3
Case III:
Therefore, f is continuous in (−3, 3).
Case IV:
It is observed that the left and right hand limit of f at x = 3 do not coincide. Therefore, f is not continuous at x = 3 Case V:
Therefore, f is continuous at all points x, such that x > 3 Hence, x = 3 is the only point of discontinuity of f.
