Positive lower bound in the punctured rectangle

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Homework Help Overview

The problem involves analyzing a positive polynomial \( p(x,y) \) of degree \( n \) that is zero only at the origin. The question is whether the quotient \( \frac{p(x,y)}{|x| + |y|^n} \) can have a positive lower bound in the punctured rectangle defined as \([-1,1] \times [-1,1] - \{(0,0)\}\).

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the nature of the polynomial, with one noting that it must have an even degree. There is a suggestion that if the quotient tends to infinity at the origin, then a positive lower bound may exist. Others question the original wording of the problem and its implications.

Discussion Status

The discussion is ongoing, with participants exploring interpretations of the problem's wording. Some have provided examples to clarify their points, while others are questioning the assumptions made about the polynomial and its behavior near the origin.

Contextual Notes

There is some ambiguity regarding the wording of the original problem, with participants suggesting that it may need to be rephrased to clarify the intent of the question.

hedipaldi
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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
 
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Have you tried a very simple example, like x^2+y^2?
 
This is not a counter example.It has a positive lower bound near the origin.
 
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?
 
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?
 
The original wording is attached:Q.5
 

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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.
 
Thank's
 

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