Can We Prove That ##A<B(\epsilon-\delta)##?

  • Context: Graduate 
  • Thread starter Thread starter amirmath
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the question of whether the inequality ##A < B(\epsilon - \delta)## can be proven given the conditions on positive numbers ##\epsilon## and ##\delta##, specifically when ##0 < \delta < \epsilon## and ##0 < A < B(\epsilon - \delta) + \epsilon C## for positive constants A, B, and C. The scope includes mathematical reasoning and inequalities.

Discussion Character

  • Mathematical reasoning

Main Points Raised

  • One participant asserts that for arbitrary positive numbers ##\epsilon## and ##\delta##, if ##0 < \delta < \epsilon##, then the inequality ##0 < A < B(\epsilon - \delta) + \epsilon C## holds, questioning if this implies ##A < B(\epsilon - \delta)##.
  • Another participant challenges the interpretation of "arbitrary," suggesting that if it means it holds for every choice of ##\epsilon## and ##\delta##, then no such positive numbers A, B, C can exist, providing an example where choosing ##\delta = \epsilon/2## leads to a contradiction.
  • A participant clarifies that they mean the inequalities hold for every choice of ##\epsilon## and ##\delta##.
  • A later reply reiterates the clarification about the inequalities holding for every choice of ##\epsilon## and ##\delta##.

Areas of Agreement / Disagreement

Participants express disagreement regarding the interpretation of "arbitrary" in the context of the inequalities, with some arguing that the statement cannot hold universally while others maintain that it does.

Contextual Notes

The discussion highlights potential limitations in the assumptions regarding the existence of positive constants A, B, and C under the stated conditions, as well as the implications of specific choices for ##\epsilon## and ##\delta##.

amirmath
Messages
8
Reaction score
0
For arbitrary positive numbers ##\epsilon## and ##\delta## we know that ##0<\delta<\epsilon## such that ##0<A<B(\epsilon-\delta)+\epsilon C## for A, B, C>0. Can we conclude ##A<B(\epsilon-\delta)##?
 
Last edited by a moderator:
Physics news on Phys.org
When you say arbitrary, do you mean it holds for every choice of epsilon and delta, or there exists some epsilon and delta? Because for the latter it's clearly not true, and for the former no such numbers A,B,C exist. For example if [itex]\delta = \epsilon/2[/itex] you get
[tex]0<A< \epsilon( B/2+C)[/tex]
And sending epsilon to 0 shows that A has to be zero which is a contradiction to it being positive
 
Thanks for your comment. I mean that the above tow inequalities hold for for every choice of epsilon and delta.
 
amirmath said:
Thanks for your comment. I mean that the above tow inequalities hold for for every choice of epsilon and delta.

Here at Physics Forums, surround your expressions with pairs of $$ or ##. A single $ doesn't do anything.
 
Thank you Mark44
 

Similar threads

  • · Replies 20 ·
Replies
20
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 25 ·
Replies
25
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K