# Relationship between asymptotes and limits

### Limits at Infinity and Asymptotes - Mathematics LibreTexts

Then we study the idea of a function with an infinite limit at infinity. .. function $$f( x)=\frac{p(x)}{q(x)}$$ depend on the relationship between the. To figure out any potential horizontal asymptotes, we will use limits . The difference between “limits at infinity” and “infinite limits” is discussed. Introduction to end behaviors, limits, asymptotes and limit notation. Limits and Asymptotes. Suppose .. Explain the difference between and.

So let's first graph two over x minus one, so let me get that one graphed, and so you can immediately see that something interesting happens at x is equal to one. If you were to just substitute x equals one into this expression, you're going to get two over zero, and whenever you get a non-zero thing, over zero, that's a good sign that you might be dealing with a vertical asymptote. In fact we can draw that vertical asymptote right over here at x equals one. But let's think about how that relates to limits.

## How are limits related to asymptotes?

What if we were to explore the limit as x approaches one of f of x is equal to two over x minus one, and we could think about it from the left and from the right, so if we approach one from the left, let me zoom in a little bit over here, so we can see as we approach from the left when x is equal to zero, the f of x would be equal to negative two, when x is equal to point five, f of x is equal to negative of four, and then it just gets more and more negative the closer we get to one from the left.

I could really, so I'm not even that close yet if I get to let's say 0.

And so the limit as we approach one from the left is unbounded, some people would say it goes to negative infinity, but it's really an undefined limit, it is unbounded in the negative direction. And likewise, as we approach from the right, we get unbounded in the positive infinity direction and technically we would say that that limit does not exist.

• 4.6: Limits at Infinity and Asymptotes

And this would be the case when we're dealing with a vertical asymptote like we see over here. Now let's compare that to a horizontal asymptote where it turns out that the limit actually can exist.

So let me delete these or just erase them for now, and so let's look at this function which is a pretty neat function, I made it up right before this video started but it's kind of cool looking, but let's think about the behavior as x approaches infinity.

Calculators and Vertical Asymptotes When a function has a vertical asymptote, a graphing calculator will often show what appears to be the graph of the asymptote along with the graph of the function.

### Module 7 - Limits and Infinity - Lesson 1

However, the calculator is actually connecting the bottom branch of the graph with the top branch. These two branches should not be connected so the calculator graph is flawed. The graph of a vertical asymptote is not part of the graph of the function. Select "Auto" for both Indpnt and Depend.

### Infinite Limit Type ( Read ) | Calculus | CK Foundation

Finding a Vertical Asymptote Analytically Factoring the numerator and denominator of a rational function and simplifying the fraction can provide information about the function near a possible asymptote. The Left-Hand Limit As x approaches 3 from the left the numerator of approaches 6 while the denominator approaches 0 through negative values.

This means the fraction will approach negative infinity. As x approaches 3 from the right the numerator of approaches 6 while the denominator approaches 0 through positive values.

## Infinite limits and asymptotes

This means the fraction will approach positive infinity. Finding a Horizontal Asymptote Analytically As the magnitude of x gets large, the term 2x2 dominates the numerator and the term x2 dominates the denominator. The end behavior of the rational function resembles the rational function.