Question

Find all points of discontinuity of f, where f is defined by

Answer 1

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 < 1 

Case II:

If c = 1, then the left hand limit of f at x = 1 is,

It is observed that the left and right hand limit of f at x = 1 do not coincide. 

Therefore, f is not continuous at x = 1 

Case III:

Therefore, f is continuous at all points x, such that x > 1 

Thus, from the above observation, it can be concluded that x = 1 is the only point of discontinuity of f.