Unit G Summary Question #7: Limit Notation for Vertical Asymptotes

7. Describe how to write limit notation for vertical asymptotes and what the notation means.

To write limit notation for vertical asymptotes, there are two parts for each asymptote. Since your equation is x=___. It is going to be a vertical line. Therefore, there can be something happening with the graph to the right and somethings happening with the graph to the left. So, for each vertical asymptote you must write the equation As x approaches the (vertical asymptote) to the RIGHT(+), f(x) approaches (either -∞ or ∞). AND As x approaches the (vertical asymptote) to the LEFT(-), f(x) approaches (either -∞ or ∞). The-∞ means that the graph is going down and the   +∞ means that the graph is going up. How do we know if it goes up ordown, you may ask? Well, you need to plug the whole equation into y= in your calculator. USING PARENTHESIS!

The vertical lines represent the asymptotes and you can clearly see, for example, As x approaches -1+, f(x) approaches ∞. And as x approaches -1-, f(x) approaches -∞