### Home > PC > Chapter 5 > Lesson 5.2.1 > Problem5-47

5-47.

Why are the following not used in limits: $x → ∞^{−}$, $x → ∞^{+}$, and $x → ∞^{+}$

Infinity is a concept of forever. It is not a real number that you can approach from the right or the left.