Proof of inner product for function space

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Discussion Overview

The discussion revolves around proving that certain expressions define a scalar product in function spaces. The focus is on demonstrating that these expressions satisfy the properties required for an inner product, with specific examples provided.

Discussion Character

  • Homework-related
  • Technical explanation

Main Points Raised

  • One participant seeks guidance on proving that two given expressions define a scalar product, suggesting that they need to show adherence to the properties of inner products.
  • Another participant questions whether the inquiry is homework-related and asks for clarification on which specific conditions are challenging to prove.
  • A further contribution highlights that the critical aspect to prove is that (f,f)=0 implies f=0, noting the necessity of continuity for the function involved.
  • Another participant prompts for a definition of "inner product" and suggests that each expression should be shown to satisfy all conditions for an inner product.

Areas of Agreement / Disagreement

Participants express differing levels of understanding and focus on various aspects of the proof, indicating that there is no consensus on how to approach the problem or which conditions are most pertinent.

Contextual Notes

There is an assumption of continuity for the functions involved, but this has not been explicitly stated in the original post. The specific function space under consideration is not clearly defined, which may affect the proof.

SFB
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Hi I am kinda new to this topic two . I was wondering how can I prove that the following expressions define scalar product. All I can guess that I need to show that they follow the properties of the scalar product.

But how? If possible, help me with an example .1. (f,g)=[tex]\int f(x)g(x)w(x)dx[/tex] where w(x)>0 where x=[0,1]
2. (f,g)=[tex]\int f'(x)g'(x)dx[/tex] +f(0)g(0)
 
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If this is homework, you should put it on the homework forums, just start a new thread. But I've already asked you, what part of the conditions for those being an inner product are you having a hard time proving?
 
The only non-trivial part is showing (f,f)=0 --> f=0. You will need continuity of f, so I think you forgot to give information about your function space (probably the space consisting of continuous functions f:[0,1]->R).
 
Show that each of those satisfies all of the conditions for an inner product. What are those conditions- that is, what is the definition of "inner product"?
 

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