Final answer:
To have a two-sided limit exist, the left and right limits must both exist, be equal to a real number, and not equal infinity.
Step-by-step explanation:
To have a two-sided limit exist, the following conditions must be met:
- Both the limit from the left and the limit from the right must exist: This means that as the input values approach the point in question from the left and the right, the function must approach a specific value.
- Both the limit from the left and the limit from the right must be equal to a real number: The left and right limits should approach the same value in order for the two-sided limit to exist.
- The limit cannot equal infinity: The function should not approach infinity as the input values approach the point in question.
Therefore, the correct answer is 3) The limit cannot equal infinity.