Proving Uniform Continuity of f+g with Triangle Inequality

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Homework Help Overview

The discussion revolves around the topic of uniform continuity in the context of functions, specifically focusing on the sum and difference of two uniformly continuous functions, f and g. The original poster presents a question regarding the uniform continuity of f + g and raises a related query about f - g.

Discussion Character

  • Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to understand the implications of uniform continuity when considering the difference of two functions, f and g, after establishing a proof for their sum. Some participants suggest that the existing proof can be adapted for f - g with minor modifications.

Discussion Status

The discussion is ongoing, with participants exploring the relationship between uniform continuity and the operations of addition and subtraction of functions. Guidance has been provided regarding the potential to apply the same reasoning used for f + g to f - g, indicating a productive direction in the conversation.

Contextual Notes

There is an implication that the original poster may be grappling with the nuances of uniform continuity and its properties, particularly in relation to the triangle inequality. The discussion also hints at the need for careful consideration of function properties when transitioning from addition to subtraction.

sergey_le
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Homework Statement
I didn't understand what I was supposed to write here
Relevant Equations
I didn't understand what I was supposed to write here
I came across the following question:
If g and f are uniform continuity functions In section I, then f + g uniform continuity In section I.
I was able to prove it with the help Triangle Inequality .
But I thought what would happen if they asked the same question for f-g
I'm sorry if my English isn't good and you don't understand me
 
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Nothing should change to your proof. Check that up to minor modifications the same proof still works.

Alternatively, if you have proven that if ##f,g## is uniformly continuous, then also ##f+g## you can proceed as follows.

Show that ##h:= -g## is uniformly continuous (this will follow because ##|-x| = |x| \forall x \in \mathbb{R}## if you do the proof) and then you can apply what you already proved: ##f+h = f-g## will be uniformly continuous.
 
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thank you
 
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sergey_le said:
thank you

Welcome to physicsforums btw! Hope you have a good time here.
 
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