Science:Math Exam Resources/Courses/MATH104/December 2013/Question 01 (l)/Solution 1
None of these have to be true! The fact that the limit exists does not imply anything about the value at that point. In fact, need not even be defined at . However, if is not defined at (C), then writing does not make sense because this value does not exist (D). can not be continuous at a point where it's not defined (B), and a function can only be differentiable at those points where it is defined and continuous (A). Therefore, the following is a counter example
Hence, the correct answer is (E).