Is a vertical asymptote possible at x=-6 if f(-6) = 3?

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Homework Help Overview

The discussion revolves around the concept of vertical asymptotes in relation to a function defined at a specific point, particularly at x = -6. The original poster questions whether a vertical asymptote can exist at this point given that the function value f(-6) is defined as 3.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the relationship between the definition of a function at a point and the existence of vertical asymptotes. The original poster presents a limit scenario, while another participant provides an example function to illustrate the concept.

Discussion Status

The discussion is active with participants questioning the implications of a function being defined at a point where a vertical asymptote is considered. There is also a new question raised regarding the limits of a piecewise function at a specific point, indicating ongoing exploration of related concepts.

Contextual Notes

Participants are examining the definitions and behaviors of functions, particularly in the context of limits and asymptotic behavior, without reaching a consensus on the implications of the definitions provided.

Loppyfoot
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Homework Statement


If f(-6) = 3, is it possible for there to be a vertical asymptote at x=-6?
The limit as x approaches -6 is positive infinity, but there f(-6) is defined by the value of -3. Or, since VAs refer to the line, the fact that f(-6) doesn't matter?
 
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How f is defined at x = -6 doesn't matter.

Here is an example function that has the behavior you describe.

f(x) = 1/(x + 6), if x != -6
f(x) = 3, if x = -6

This function has a vert. asymptote at x = -6, even though f(-6) is defined.
 
Thanks!
Another question:
For the piecewise,
f(x){-x+1 , 0<=x<1
{1, 1<=x<2
What is the limit as x approaches 1?

Do I do?
-x+1 = 1
-x=0
x=0?
So 0+1 = 1
and 1
So the limit is 1? Or does it not exist?
 
For a limit to exist, both one-sided limits must exist and must be equal.
So you need to find these limits:
[tex]\lim_{x \rightarrow 1^+}f(x)[/tex]
[tex]\lim_{x \rightarrow 1^-}f(x)[/tex]
If both exist and are equal, then
[tex]\lim_{x \rightarrow 1}f(x)[/tex]
exists and is equal to the common value.
 

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