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

The given function is 
We know that if x < 0
⇒ |x| = -x
So, we can rewrite the given function as:

⇒ f(x) = -1 for all x ϵ R
Let k be the point on a real line.
Then, f(k) = -1
= -1= f(k)
Thus, ![]()
Therefore, the given function is a continuous function.