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

The given function is

The function f is defined at all points of the real line.


Let k be the point on a real line.


Then, we have 3 cases i.e., k < 2, or k = 2 or k > 2


Now, Case I: k < 2


Then, f(k) = k3 - 3


= k3 - 3= f(k)


Thus,


Hence, f is continuous at all real number less than 2.


Case II: k = 2


Then, f(k) = f(2) = 23 - 3 = 5


= 23 - 3 = 5


= 22 + 1 = 5



Hence, f is continuous at x = 2.


Case III: k > 2


Then, f(k) = 22 + 1 = 5


= 22 + 1 = 5 = f(k)


Thus,


Hence, f is continuous at all real number greater than 2.


11