Archimedean property of R proof

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SUMMARY

The discussion focuses on proving the Archimedean property of real numbers (R) using the density of rational numbers (Q) within R. The Archimedean property asserts that for every real number x, there exists a natural number y such that y > x. The proof involves demonstrating that for any real number x, whether positive or negative, a rational number q can be found such that x < q < x + 1, thereby establishing the required relationship.

PREREQUISITES
  • Understanding of real numbers (R) and rational numbers (Q)
  • Familiarity with the concept of density in mathematics
  • Knowledge of the Archimedean property
  • Basic algebraic manipulation involving integers and fractions
NEXT STEPS
  • Study the proof of the density of Q in R
  • Explore the implications of the Archimedean property in real analysis
  • Investigate the relationship between rational and irrational numbers
  • Learn about the completeness property of real numbers
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Mathematics students, educators, and anyone interested in real analysis or foundational properties of numbers.

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Homework Statement


Using the density of Q(rationals) in R(real numbers), prove the Archimedean property.


Homework Equations


Density of Q in R: For all x,y in R, and x<y, there exists q in Q s/t x<q<y.
Archimedean property says: For every real number x there exists a natural number y such that y>x.


The Attempt at a Solution


So I know how to prove the density of Q in R using the Archimedean property but I'm not sure of how to do it the other way around. Also, I don't really understand why it makes sense to prove it the other way around? Any hints and explanations would be helpful! thanks
 
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The problem does seem that hard. If x is negative y can be 1. If x is positive you know that

x< q < x+1

where q is a positive rational

or
x< q = s/t

Remember what a rational number is ,that is, s and t are integers. You may also have to assume that s and t have no common factors eg we write 3/2 not -3/-2 :-).
 

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