Finding the limit of a function as x approaches a.

In summary, a limit is the value that a function approaches as the input approaches a certain value. It can be calculated using various techniques and helps us understand the behavior and properties of a function. A limit can exist even if the function is not defined at that point, and it differs from the value of the function at a specific point.
  • #1
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For the function, f(x)=x^2 I need to find the limit as x approaches a. I am sure the limit is a^2, but how can I prove this, should I use the epsilon delta method? if so, am I to set delta to [tex]\sqrt{}epsilon[/tex]?
thanks
 
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  • #2
Why don't you try it.

Let [itex]\epsilon > 0[/itex] and set [itex]\delta = \sqrt{\epsilon}[/itex].
If [itex]|x - a| < \delta[/itex] then
[tex]|f(x) - a^2| = |x^2 - a^2| = \cdots \le \cdots \stackrel{?}{\le} \epsilon[/tex]
 

FAQ: Finding the limit of a function as x approaches a.

What is the definition of a limit?

A limit is the value that a function approaches as the input (usually represented by x) approaches a certain value. It is a fundamental concept in calculus and is used to describe the behavior of a function near a specific point.

How is a limit calculated?

Limits can be calculated using various techniques, such as substitution, factoring, and the use of limits laws. The most common method is to plug in values that are close to the desired input value and observe the output values to determine the limit.

3. What is the significance of finding the limit of a function?

Finding the limit of a function helps us understand the behavior and properties of the function. It can help determine if a function is continuous, identify asymptotes, and calculate derivatives and integrals.

4. Can a limit exist even if the function is not defined at that point?

Yes, a limit can exist even if the function is not defined at that point. This is known as a "removable discontinuity" and occurs when the function has a hole or gap at that point. The limit can still be found by evaluating the function at values close to the desired input.

5. How is the limit of a function different from the value of the function at a specific point?

The limit of a function describes the behavior of the function near a specific point, while the value of the function at a specific point is the output of the function when the input is that particular value. The limit can exist even if the function is not defined at that point, whereas the value of the function only exists when the input matches the specific point.

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