Understanding Mean Value Theorem: Solving Homework Problems

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Homework Help Overview

The discussion revolves around understanding the Mean Value Theorem and its relationship to Rolle's Theorem, as well as addressing specific statements related to these theorems. Participants are examining the correctness of various assertions made in a homework problem.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are analyzing specific statements about theorems, questioning their validity, and discussing the implications of continuity and differentiability in the context of the theorems.

Discussion Status

Some participants have provided insights into the definitions and conditions of the theorems, while others express uncertainty about specific statements. There is an ongoing exploration of the nuances in the definitions, particularly regarding continuity at the endpoints of the interval.

Contextual Notes

There is mention of textbook references and a library item that may clarify the definitions, indicating that participants are working within the constraints of their course materials and homework guidelines.

Slimsta
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Homework Statement


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Homework Equations





The Attempt at a Solution


the first 3 are from the textbook so they must be right.. the last 2 I am pretty sure i got right too..
because the 4th one, if f'(x)=0 then f(x)= c .. so its false.
im not too sure about the 5th one but I am 90% sure it should true.
 
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(1) is Rolle's Theorem (Edit: this is incorrect - see the following posts)
(2) is the Mean Value Theorem, which is a generalization of Rolle's Theorem
I did not know (3) but that is interesting
(4) is correct, f(x) can be a constant function not equal to 0.
(5) is correct - take a(x) = f(x) - g(x). It's derivative is 0, so a(x) is constant (you can prove this using MVT).
 
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VeeEight said:
(1) is Rolle's Theorem
(2) is the Mean Value Theorem, which is a generalization of Rolle's Theorem
I did not know (3) but that is interesting
(4) is correct, f(x) can be a constant function not equal to 0.
(5) is correct - take a(x) = f(x) - g(x). It's derivative is 0, so a(x) is constant (you can prove this using MVT).

i know that 1 and 2 are Rolle's Theorem and Mean Value Theorem, and its written exactly like in my textbook.. i can't find the mistake.

https://www.physicsforums.com/library.php?do=view_item&itemid=231 its even stated here..

so what is wrong?
 
Oh sorry, I missed that
(1) states that f is defined on [a,b] but it is not necessarily continuous there. It is continuous on (a,b) (since it is differentiable there) but not necessarily at a or b.
 
VeeEight said:
Oh sorry, I missed that
(1) states that f is defined on [a,b] but it is not necessarily continuous there. It is continuous on (a,b) (since it is differentiable there) but not necessarily at a or b.

thats a tricky question.. weird.
thanks a lot for your help man!
 
No problem, can't believe I missed that
In my experience, the physical science courses are where they try to 'trick' you like that, I've never had any questions like that when I was a math undergrad. I guess now you've learned that you have to pay attention to every little detail when writing tests in this class (which is probably a good idea, regardless). Cheers.
 

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