Is the limit of 1/x^2 as x approaches 0 non-existent?

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In summary, the conversation discusses the limit of a function as x approaches 0 and whether it exists or not. It is concluded that the limit does not exist and a definition for a limit of infinity is provided.
  • #1
JG89
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Obviously [tex] \lim_{x \rightarrow 0} \frac{1}{x^2} = \infty [/tex], but am I correct in saying that the limit as x approaches 0 of [tex] \frac{1}{x^2}[/tex] doesn't exist?

If it did exist then one of the conditions would be, for values of x sufficiently close to 0, [tex]|x-\infty| = \infty < \delta[/tex] which obviously isn't true for all positive values of delta. Am this correct?
 
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  • #2
I think you are correct in saying that the limit does not exist. However,

[tex]\lim_{x \rightarrow a} f(x) = \infty [/tex] means that for every [tex]N \in \Re[/tex] there exists a number [tex]\delta > 0[/tex] such that, for all x,
if [tex]0 < |x-a| < \delta[/tex], then [tex]f(x) > N[/tex].
 
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  • #3
I don't know how I made that mistake :rofl:

Thanks for the reply though :)
 

What is a limit?

A limit is a fundamental concept in calculus that describes the behavior of a function as the input approaches a certain value. It represents the value that a function "approaches" but may not necessarily reach at that specific input.

Why do we use limits?

Limits are used to analyze the behavior of a function at specific points, such as when the input approaches a certain value or when it approaches positive or negative infinity. They are also used to define important concepts in calculus, such as continuity and differentiability.

How do we find limits?

The limit of a function can be found by evaluating the function at points closer and closer to the desired input value. This can be done algebraically, graphically, or using techniques such as L'Hopital's rule or the Squeeze theorem.

What is the difference between a one-sided limit and a two-sided limit?

A one-sided limit only considers the behavior of the function as the input approaches the desired value from one side, either the left or right. A two-sided limit considers the behavior from both sides and only exists if the left and right limits are equal.

What does it mean for a limit to not exist?

A limit does not exist if the function behaves differently from different directions as the input approaches the desired value. This can occur if the function has a vertical asymptote or a jump discontinuity at that point.

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