Proving Limit Exists: x-2 of f(x)=2

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In summary, the conversation discusses how to prove that a delta exists such that when [x] < delta, then f(x) > 1 using the delta, epsilon definition of a limit. One participant suggests using the equation [x-a] < delta such that f(x) > 1, but they are unsure how to prove it. The conversation ends with the question of whether f(x) = 2 is a constant function or if the limit is being proven. The thread is then closed and the participants are asked to repost their question.
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rb120134
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Homework Statement
Prove that delta>0 exists such that f(x)>1 using delta epsilon definition
Relevant Equations
[x-a]<delta such that f(x)>1
Given is the following: lim x-2 of f(x)=2 prove (using delta, epsilon definition of a limit) that a delta exists so that when [x]<delta then f(x)>1
I came up with when [x-a]<delta (f(a)-epsilon<f(x)< f(a) + epsilon) so f(a)-epsilon>1 so epsilon<f(a) -1 but I don't know how to prove this or how to answer this question?
 
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Perhaps someone else can make sense of that, but that is just a muddle to me. What is the question exactly?
 
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rb120134 said:
Homework Statement:: Prove that delta>0 exists such that f(x)>1 using delta epsilon definition
Relevant Equations:: [x-a]<delta such that f(x)>1

Given is the following: lim x-2 of f(x)=2 prove (using delta, epsilon definition of a limit) that a delta exists so that when [x]<delta then f(x)>1
I came up with when [x-a]<delta (f(a)-epsilon<f(x)< f(a) + epsilon) so f(a)-epsilon>1 so epsilon<f(a) -1 but I don't know how to prove this or how to answer this question?
I agree with PeroK's assessment.
Is it given that f(x) = 2 is a constant function, or are you trying to prove this limit?
$$\lim_{x \to 2} f(x) = 2$$

Thread closed. Please repost your question.
 

FAQ: Proving Limit Exists: x-2 of f(x)=2

What does it mean to prove the limit exists for a function?

Proving the limit exists for a function means showing that as the input approaches a certain value, the output of the function also approaches a specific value. In other words, the function becomes more and more consistent as the input gets closer to a particular value.

Why is it important to prove the limit exists for a function?

Proving the limit exists for a function is important because it helps us understand the behavior of the function near a specific point. This information is crucial in many mathematical and scientific applications, such as calculating derivatives and integrals.

How do you prove the limit exists for a function?

To prove the limit exists for a function, you need to show that the left and right limits of the function at a specific point are equal. This can be done using various methods, such as the epsilon-delta definition or the squeeze theorem.

What is the role of continuity in proving the limit exists for a function?

Continuity is closely related to the concept of a limit. A function is said to be continuous at a point if its limit exists at that point and is equal to the value of the function at that point. Therefore, continuity is necessary for proving the limit exists for a function.

Can the limit of a function exist at one point but not at another?

Yes, it is possible for the limit of a function to exist at one point but not at another. This can happen if the function is discontinuous or has a jump or hole at the point in question. It is important to consider the behavior of the function at each point individually when proving the limit exists.

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