Left & Right Limits Of A Function (Finding Values Of A Variable)

Click For Summary
The discussion revolves around understanding how to find the value of "m" in the context of left and right limits of a function. Participants initially express confusion about the problem, particularly regarding the absence of specific x or y coordinates. The key equation discussed is the limit as x approaches 1, specifically \lim_{x\to\,1}(8x^3-2m), which participants clarify can be evaluated directly. Ultimately, it is concluded that the limit simplifies to 8 - 2m, leading to a realization that the problem was less complex than initially perceived. The conversation highlights the importance of correctly interpreting limit problems in calculus.
CallMeShady
Messages
45
Reaction score
1

Homework Statement


11rddt5.jpg



Homework Equations


Only ones I know that are relevant are the equations shown in the question (for the left and right limits).


The Attempt at a Solution


The difficulty that I am having right not is comprehending what is really being asked from the question. From what I understand, then question is asking the "m" values from the left and right limits at the top, and the value for "m" when those limits are the same. However, how would I go about finding the value of "m" if I have no x or y co-ordinates given?
 
Physics news on Phys.org
CallMeShady said:

Homework Statement


11rddt5.jpg



Homework Equations


Only ones I know that are relevant are the equations shown in the question (for the left and right limits).


The Attempt at a Solution


The difficulty that I am having right not is comprehending what is really being asked from the question. From what I understand, then question is asking the "m" values from the left and right limits at the top, and the value for "m" when those limits are the same. However, how would I go about finding the value of "m" if I have no x or y co-ordinates given?
What is \displaystyle \lim_{x\to\,1}(8x^3-2m)\ ?
 
SammyS said:
What is \displaystyle \lim_{x\to\,1}(8x^3-2m)\ ?

That is not given (everything above that I posted is the only thing given). Or are you suggesting that I should calculate that to solve this problem. That expression just defines the limit from the left side. I am unsure on how to calculate that.
 
CallMeShady said:
That is not given (everything above that I posted is the only thing given). Or are you suggesting that I should calculate that to solve this problem. That expression just defines the limit from the left side. I am unsure on how to calculate that.
What do you mean, it's not given?

I'm asking you to evaluate the limit, \displaystyle \lim_{x\to\,1}(8x^3-2m)\,, if you can. If you can't, I don't how you can do this problem at all.
 
SammyS said:
What do you mean, it's not given?

I'm asking you to evaluate the limit, \displaystyle \lim_{x\to\,1}(8x^3-2m)\,, if you can. If you can't, I don't how you can do this problem at all.


I don't see how I can evaluate that limit... I could isolate "m" though by temporarily assigning "f(x)" as "y". Then I could isolate "m" in terms of "y" => "m(y)".
 
Sammy is not asking you to solve for m (i.e., isolate me) - just evaluate the limit, which by the way should be
$$\lim_{x \to -1^{-}}(8x^3 - 2m) $$

Your answer should be in terms of m.
 
CallMeShady said:
I don't see how I can evaluate that limit... I could isolate "m" though by temporarily assigning "f(x)" as "y". Then I could isolate "m" in terms of "y" => "m(y)".
\displaystyle \lim_{x\to\,1}(8x^3-2m) = 8(1)^3-2m=8-2m

That's all there is to it !
 
I can't believe how easy this question actually was... I was making it too complex due to the fact that I wasn't comprehending this question very well. A sincere thank you to Mark and Sammy for their assistance. I really appreciate it.
 
Last edited:
CallMeShady said:
I can't believe how easy this question actually was... I was making it too complex due to the fact that I wasn't comprehending this question very well. A sincere thank you to Mark and Sammy for their assistance. I really appreciate it.

So, what are you results?
 

Similar threads

  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
3
Views
1K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K