Reals under multiplication homomorphisms

In summary, a function f:R-->R^x is a homomorphism if and only if f(x+y) = f(x) + f(y) for all x,y in R. R^x refers to the multiplicative reals, and the function must also satisfy the condition that f(0) = 1. This statement is false, as it cannot hold for all a,b in R^x.
  • #1
ldelong
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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.
 
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  • #2
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.)
 
  • #3
Thanks Matt, I was unsure as to what R^x was and how it worked.
 

1. What is a "Reals under multiplication homomorphisms"?

Reals under multiplication homomorphisms, also known as real numbers under multiplication homomorphisms, refer to a mathematical structure in which the set of real numbers is equipped with a binary operation of multiplication that preserves the algebraic structure of the real numbers.

2. How are "Reals under multiplication homomorphisms" different from regular real numbers?

The main difference is that "Reals under multiplication homomorphisms" include an additional operation, multiplication, that follows specific rules and properties. This allows for a more comprehensive understanding and study of the real numbers.

3. What are some common properties of "Reals under multiplication homomorphisms"?

Some common properties include closure, associativity, commutativity, identity element (1), and inverse elements (for non-zero numbers). These properties ensure that the operation of multiplication on the real numbers is consistent and follows specific rules.

4. How are "Reals under multiplication homomorphisms" used in real-world applications?

"Reals under multiplication homomorphisms" are used in various fields such as physics, engineering, and economics to model and solve real-world problems. They provide a precise and consistent way of representing and manipulating quantities and measurements.

5. What are some important theorems related to "Reals under multiplication homomorphisms"?

Some important theorems include the Fundamental Theorem of Arithmetic, which states that every positive integer can be uniquely represented as a product of prime numbers, and the Zero Product Property, which states that if the product of two real numbers is equal to zero, then at least one of the numbers must be zero.

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