Prove the following is a convex set?

In summary, the conversation discusses the problem of proving that a set F is convex, where x is a non-negative vector in R^n and A and b are arbitrary numbers. The concept of convexity is briefly mentioned, but there is confusion over the meaning of vectors being greater than numbers.
  • #1
ashina14
34
0

Homework Statement


Prove that F = {x E R^n : Ax >/= b; x >/= 0} is a convex
set.

Yes x in non negative and A and b are any arbitrary


Homework Equations






The Attempt at a Solution



Well I know A set T is convex if x1, x2 E T implies that px1+(1-p)x2 E T for all 0 <= p <= 1.
I don't know how to use this information.
 
Physics news on Phys.org
  • #2
ashina14 said:

Homework Statement


Prove that F = {x E R^n : Ax >/= b; x >/= 0} is a convex
set.

Yes x in non negative and A and b are any arbitrary

Are arbitrary what? What does it mean for ##x\in R^n## to satisfy ##x > 0##?
 
  • #3
A and b are any arbitrary number in R.
All vectors in x E Rn are non-negative
 
  • #4
ashina14 said:

Homework Statement


Prove that F = {x E R^n : Ax >/= b; x >/= 0} is a convex
set.

LCKurtz said:
Are arbitrary what? What does it mean for ##x\in R^n## to satisfy ##x > 0##?

ashina14 said:
A and b are any arbitrary number in R.
All vectors in x E Rn are non-negative

This doesn't make any sense to me. If x is a vector and A is a real number then Ax is a vector. If b is a real number you have the vector Ax > b, a real number. What does it mean for a vector to be greater than a number? It makes about as much sense to say an apple is greater than a bicycle.
 
  • #5
I'm so sorry. b is a vector too. I don't understand this topic too well.
 
  • #6
That doesn't help. What does it mean for one vector to be greater than another?
 

Related to Prove the following is a convex set?

1. What is a convex set?

A convex set is a set of points where, for any two points within the set, the line segment connecting them is also within the set. In other words, all points on the line connecting any two points in the set are also part of the set.

2. How do you prove a set is convex?

To prove a set is convex, you must show that for any two points within the set, the line segment connecting them is also within the set. This can be done by using the definition of convexity and showing that it holds true for all points in the set.

3. What is the importance of convex sets in science?

Convex sets are important in science because they have many real-world applications, such as in optimization problems, economics, and physics. They also have useful properties, such as having a unique minimum and being easy to analyze mathematically.

4. Can a set be both convex and concave?

No, a set cannot be both convex and concave. A convex set is one where all points on the line segment connecting any two points in the set are also part of the set, while a concave set is one where all points on the line segment connecting any two points in the set are not part of the set. These are two opposite properties and cannot both be true for the same set.

5. How can I use convex sets in my research or experiments?

Convex sets can be used in a variety of ways in research or experiments. For example, they can be used to model optimization problems, analyze economic systems, or understand the behavior of physical systems. By understanding and utilizing convex sets, you can solve complex problems and gain insights into your research or experiments.

Similar threads

  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
8
Views
1K
  • Calculus and Beyond Homework Help
Replies
6
Views
1K
  • Calculus and Beyond Homework Help
Replies
6
Views
1K
Replies
4
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
Replies
9
Views
549
  • Calculus and Beyond Homework Help
Replies
8
Views
2K
Replies
5
Views
1K
Back
Top