Proving vector space, associativity

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SUMMARY

The discussion focuses on proving the associativity property in the context of an abelian group with scalar multiplication, specifically examining the equality exp(b.c.lnx) = b.exp(c.lnx). The conclusion drawn is that these expressions are not equal, as demonstrated through the properties of logarithms and exponentials. The participant correctly identifies that e^x and ln x are inverses, leading to the simplification x^{bc} = bx^c, which does not hold true. A counter-example using specific values (x=3, b=2, c=1) further confirms this result.

PREREQUISITES
  • Understanding of abelian groups and their properties
  • Familiarity with scalar multiplication in vector spaces
  • Knowledge of logarithmic and exponential functions
  • Basic algebraic manipulation skills
NEXT STEPS
  • Study the properties of abelian groups in depth
  • Learn about scalar multiplication in vector spaces
  • Review the laws of logarithms and exponentials
  • Explore counter-examples in mathematical proofs
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Students studying abstract algebra, mathematicians interested in vector space theory, and anyone working on proofs involving logarithmic and exponential functions.

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Homework Statement


Im doing a problem where I am trying to show that an abelian group with a scalar multiplication is a vector field. I am trying to show associativity right now and just have a question:

im trying to show that exp(b.c.lnx) = b.exp(c.lnx)

But I am not very sure of my logs and exp's laws, not sure that they are even equal. Any pointers guys?


Homework Equations





The Attempt at a Solution

 
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They wouldn't be equal.

Since e^x and \ln x are inverses of each other, e^{\ln x} = x. Therefore, your expressions can be simplified to x^{bc} = bx^c which are not equal.

Also, a simple counter-example shows the same result: Taking x=3, b=2, c=1 we have 3^{1\cdot 2}=2\cdot 3^1 which is obviously not true.
 

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