Reals under multiplication homomorphisms

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SUMMARY

The discussion centers on the properties of homomorphisms from the real numbers R to the multiplicative group of non-zero real numbers R^x. It is established that a function f: R → R^x is a homomorphism if and only if it satisfies the condition f(x+y) = f(x) + f(y) for all x, y in R. However, this statement is false, as it contradicts the fundamental properties of homomorphisms, specifically that a homomorphism must map the additive identity (0) to the multiplicative identity (1). The confusion arises from the interpretation of R^x, which denotes the multiplicative reals.

PREREQUISITES
  • Understanding of homomorphisms in group theory
  • Familiarity with the structure of the real numbers R
  • Knowledge of the multiplicative group of non-zero real numbers R^x
  • Basic principles of algebraic structures and identities
NEXT STEPS
  • Study the properties of group homomorphisms in detail
  • Learn about the structure and properties of the multiplicative group of reals
  • Explore examples of homomorphisms between different algebraic structures
  • Investigate the implications of mapping identities in group theory
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Mathematicians, students studying abstract algebra, and anyone interested in the properties of homomorphisms and group theory.

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Homework Statement


A function f:R-->R^x is a homomorphism iff f(x+y) = f(x) + f(y) for all x,y in R


Homework Equations



I don't know what group R^x is. I can only assume it means Reals under multiplication . Would that mean that f(x+y) = f(x)f(y)? How does the function work? Since 5 is in R what would it be mapped to in t R^x?


The Attempt at a Solution



This isn't a homework question, I read it in the book as a false statement but there was no explanation as to what R^x was and I couldn't understand why it was false.
 
Last edited:
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R^[symbol that looks like a multiplication sign] is indeed the multiplicative reals.

I don't under stand what you're asking. Are you asserting that you know this statement that you imply to be true is actually false? (It is false, by the way, and trivially so - it cannot be that a+b=ab for all a,b in R^x, or for all a,b in a non-trivial subgroup of R^x: any homomorphism of this kind must send 0 to 1.)
 
Thanks Matt, I was unsure as to what R^x was and how it worked.
 

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