Lipschitz Q: Show w/ Example & Derivative

In summary, the conversation discusses the requirements of a homework problem involving a general function, and the necessity of proving it for all functions rather than just one example. The speaker also notes that using one example may help develop intuition, but ultimately the proof must be done for the general case.
  • #1
JasMath33
21
1

Homework Statement


upload_2016-7-5_10-31-39.png

Homework Equations

The Attempt at a Solution


I know I will just have to show this by one example. I thought about using f(x) = x2 but I am not sure if this satisfies the last part dealing with the absolute value of the derivative. It is just the last part on which I am stuck.
 
Physics news on Phys.org
  • #2
JasMath33 said:

Homework Statement


View attachment 102885

Homework Equations

The Attempt at a Solution


I know I will just have to show this by one example. I thought about using f(x) = x2 but I am not sure if this satisfies the last part dealing with the absolute value of the derivative. It is just the last part on which I am stuck.

Just showing it for one example will not satisfy the requirements of the question.
 
  • #3
Ray Vickson said:
Just showing it for one example will not satisfy the requirements of the question.
But I don't need to prove it for all functions. Why would not showing one work?
 
  • #4
JasMath33 said:
But I don't need to prove it for all functions. Why would not showing one work?

You have mis-read the question. It hypothesized some properties of an uspecfied, general function ##f(x)## and asked you to prove something else about that function. Showing it for just one function alone won't work; how do you know it would be true for some other function that you did not use?

Of course, showing it for one function privately (for your own background use only) may help you to develop the needed intuition about the problem, thus allowing you to extend the ideas to the general case, but doing the general case is absolutely required.
 

1. What is the Lipschitz condition?

The Lipschitz condition is a mathematical concept used to describe the smoothness or regularity of a function. It states that for a function f, there exists a constant K such that the absolute value of the difference between the outputs of f at any two points is less than or equal to K times the absolute value of the difference between the inputs of those points.

2. How is the Lipschitz condition related to continuity?

The Lipschitz condition is a stronger version of continuity. A function that satisfies the Lipschitz condition is automatically continuous, but the converse is not true.

3. Can you provide an example of a Lipschitz function?

One example of a Lipschitz function is the absolute value function, f(x) = |x|. It satisfies the Lipschitz condition with K = 1, as the absolute value of the difference between any two inputs is always less than or equal to 1 times the absolute value of the difference between those inputs.

4. How is the Lipschitz condition used in optimization problems?

In optimization problems, the Lipschitz condition is used to guarantee the existence and uniqueness of a solution. It also helps in finding a more efficient algorithm for finding the optimal solution.

5. What is the derivative of a Lipschitz function?

The derivative of a Lipschitz function exists everywhere except at a countable number of points. It is also bounded by the Lipschitz constant K, meaning that the absolute value of the derivative is always less than or equal to K.

Similar threads

  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
4
Views
6K
  • Calculus and Beyond Homework Help
Replies
5
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
2K
  • Calculus and Beyond Homework Help
Replies
4
Views
2K
  • Calculus and Beyond Homework Help
Replies
5
Views
2K
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
Replies
3
Views
1K
  • Differential Equations
Replies
2
Views
2K
Back
Top