Intermediate value theorem problem

In summary, the conversation discusses how to prove that if a function F is continuous, then there exists a fixed point of F in the interval [0,1]. The participants suggest using the intermediate value theorem and drawing a picture to understand the concept better. They also mention that the function is bijective and that there is a point c in the interval [0,1] such that F(c)=c. They also mention that F(0) and F(1) have certain properties that can be used to prove the existence of a fixed point.
  • #1
shrug
6
0
1. How can you prove if F is continuous, then there exists a fixed point of F in [0,1]?



I know F:[0,1] ---> [0,1] an bijective, but what is f(c)=c mean?
 
Physics news on Phys.org
  • #2


Have you tried drawing a picture? It might be enlightening.
 
  • #3


I think it means more or less exactly what it says. There is a c in [0,1] such that F(c)=c. Use the intermediate value theorem. If F is bijective there is an a such that F(a)=0 and a b such that F(b)=1. What happens in between? Apply the IVT to F(x)-x on the interval [a,b].
 
  • #4


Dick said:
I think it means more or less exactly what it says. There is a c in [0,1] such that F(c)=c. Use the intermediate value theorem. If F is bijective there is an a such that F(a)=0 and a b such that F(b)=1. What happens in between? Apply the IVT to F(x)-x on the interval [a,b].

Does that mean I need to pick a point like .5, which is between [0,1].

Also, would there be any point where F isn't continuous and a fixed point may not exist.

Thanks guys
 
  • #5


I don't think you really understood what I wrote. As morphism said, draw a picture. Look up the IVT.
 
  • #6


No, you can't "pick" a point. And you are told that the function is continuous. Why are you asking if it isn't?

If F is from [0, 1] what can you say about F(0)? What can you say about F(1)?

What can you say about 0- F(0) and 1- F(1)?
 

1. What is the Intermediate Value Theorem?

The Intermediate Value Theorem is a mathematical concept that states that if a continuous function has a different sign at each end of an interval, then it must have at least one root (or zero) within that interval.

2. How is the Intermediate Value Theorem used in problem-solving?

The Intermediate Value Theorem is used to prove the existence of solutions or roots in a given interval for a continuous function. This can be helpful in solving equations or problems where the exact solution cannot be found algebraically.

3. What are the conditions for the Intermediate Value Theorem to be applied?

The Intermediate Value Theorem can only be applied to continuous functions. This means that the function must be defined and continuous over the entire interval in question.

4. Can the Intermediate Value Theorem be used to find the exact value of a solution?

No, the Intermediate Value Theorem can only prove the existence of a solution within an interval, but it does not provide the exact value of the solution. Additional methods, such as numerical approximations or algebraic manipulation, must be used to find the exact value.

5. Are there any limitations to the Intermediate Value Theorem?

Yes, the Intermediate Value Theorem can only be used to find a solution within a given interval. It does not provide any information about the number of solutions or their exact locations. Additionally, the function must be continuous for the theorem to be applied, which may not always be the case in real-world situations.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
980
  • Calculus and Beyond Homework Help
2
Replies
58
Views
3K
  • Calculus and Beyond Homework Help
Replies
12
Views
1K
  • Calculus and Beyond Homework Help
Replies
14
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
257
  • Calculus and Beyond Homework Help
Replies
14
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
495
  • Calculus and Beyond Homework Help
Replies
15
Views
1K
  • Calculus and Beyond Homework Help
Replies
19
Views
1K
Replies
1
Views
908
Back
Top