Positive lower bound in the punctured rectangle

  • Thread starter hedipaldi
  • Start date
  • Tags
    Bound
In summary, the conversation discusses the possibility of a positive lower bound for the quotient p(x,y)/[absolute value(x)+absval(y)]^n in the punctured rectangle [-1,1]x[-1,1]-{(0,0)}, where p(x,y) is a positive polynomial of even degree that is only equal to 0 at the origin. It is suggested that such a lower bound may exist if p(x,y) is homogeneous. Further discussion and clarification is needed to determine if this is guaranteed for all p(x,y) in the given conditions.
  • #1
hedipaldi
210
0

Homework Statement




Let p(x,y) be a positive polynomial of degree n ,p(x,y)=0 only at the origin.Is it possible that
the quotient p(x,y)/[absolute value(x)+absval(y)]^n will have a positive lower bound in the punctured rectangle [-1,1]x[-1,1]-{(0,0)}?

Homework Equations





The Attempt at a Solution


I observed that p(x,y) must have even degree.Also if the quotient tend to infinity at the origin the answer is yes.Otherwise p(x,y) must be hogeneous,and this may imly that the quotient has a positive lower bound.I need help for progressing
 
Physics news on Phys.org
  • #2
Have you tried a very simple example, like x^2+y^2?
 
  • #3
This is not a counter example.It has a positive lower bound near the origin.
 
  • #4
hedipaldi said:
This is not a counter example.It has a positive lower bound near the origin.

... and therefore it is possible. Are you sure the wording of the OP is as you intend?
 
  • #5
As i understood,the meaning is to show that for every such p(x,y) there exists such C.
How do you understatd the wording?
 
  • #6
The original wording is attached:Q.5
 

Attachments

  • 001.jpg
    001.jpg
    15 KB · Views: 351
  • #7
The original wording makes more sense. To express it you should have written "Is it guaranteed that..."
If I have any helpful thoughts I'll post again.
 
  • #8
Thank's
 

1. What is a lower bound?

A lower bound is the smallest possible value that a variable or function can have within a given set of constraints or conditions.

2. How is a lower bound determined?

A lower bound is typically determined through mathematical analysis or experimentation. It may also be derived from known properties or limitations of a system or process.

3. What is the significance of a lower bound?

A lower bound is important because it sets a limit on the possible values that a variable or function can take. It can provide insight into the behavior and limitations of a system or process.

4. Can a lower bound change over time?

Yes, a lower bound can change over time as new information or data is discovered. It may also change depending on the specific conditions or constraints being considered.

5. How does a lower bound differ from an upper bound?

A lower bound is the smallest possible value, while an upper bound is the largest possible value. They represent opposite ends of a range of possible values for a variable or function.

Similar threads

  • Calculus and Beyond Homework Help
Replies
7
Views
2K
  • Calculus and Beyond Homework Help
Replies
12
Views
2K
  • General Math
Replies
8
Views
4K
  • Precalculus Mathematics Homework Help
Replies
4
Views
2K
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
2K
  • Calculus and Beyond Homework Help
Replies
4
Views
3K
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
Back
Top