If
For what value (s) of a does
exists?
Given function is 
There are three cases.
Case 1: When a = 0
:
⇒ ![]()
⇒ ![]()
Here ![]()
∴
does not exist.
Case 2: When a < 0
:
⇒ ![]()
⇒ ![]()
∴ ![]()
∴ lim(f(x)) exists at x = a when a < 0
Case 3: When a > 0
:
⇒ ![]()
⇒ ![]()
∴ ![]()
∴ lim(f(x)) exists at x = a when a > 0
Ans.
exists for all a ≠ 0