Limit as x Approaches 5: Right = 3, Left = 8, Does Not Exist?

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In summary, the homework statement provides a function f(x) with two different expressions for x values less than or equal to 5 and greater than 5. The task is to find the limit of f(x) as x approaches 5 from the left, right, and at x = 5. The correct answers are 8 from the left, 3 from the right, and the limit does not exist at x = 5. The person initially made a mistake by reversing the directions but has since corrected it. However, their friend's webworks system still marks it as incorrect.
  • #1
OrbitalPower

Homework Statement


Says: Let [tex] f(x) = x + 3[/tex] if [tex]x \le5[/tex] and
f(x) = 3 if [tex]x > 5[/tex]

And then it asks you to find the limit as x approaches 5 from the left, right, and as x = 5.

I get 3 as x approaches from the right, 8 from the left, and does not exist other words. But he says that's not correct. What am I doing wrong.
 
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  • #2
Sounds like you reversed the directions.
 
  • #3
Yah, I did. I reversed it as a wrote it, but I fixed it. Otherwise it is correct?

When x approaches 3 from the left, I should get 8. And from the right, i should get 3. And I don't think it exists at x = 5.

This is for a friend but his webworks says that's wrong.
 
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  • #4
Yep.
 
  • #5
cool thanks. I think an email needs to be sent.
 

1. What does "limit as x approaches 5" mean?

When we talk about the limit as x approaches 5, we are referring to the behavior of a function as the input values (x) get closer and closer to the value 5. This is also known as the limit of a function at a specific point.

2. What does "Right = 3" mean in this context?

In this context, "Right = 3" means that when x approaches 5 from the right (values greater than 5), the function approaches the value 3. This can also be written as "lim x→5+ f(x) = 3".

3. What does "Left = 8" mean in this context?

Similarly, "Left = 8" means that when x approaches 5 from the left (values less than 5), the function approaches the value 8. This can also be written as "lim x→5- f(x) = 8".

4. What does "Does Not Exist" mean in this context?

In this context, "Does Not Exist" means that the limit of the function at x=5 does not exist. This can happen when the left and right limits are not equal, or when the function has a discontinuity at x=5.

5. How can we determine the value of the limit as x approaches 5 in this case?

Since the left and right limits are not equal and the limit does not exist, we cannot determine the value of the limit as x approaches 5 in this case. More information about the function would be needed to determine the behavior at x=5.

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