Can You Find an Irrational Number Between Two Rational Fractions?

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Homework Help Overview

The discussion revolves around finding an irrational number that lies between two rational fractions represented as a/b and c/d, where a, b, c, and d are integers with b and d being positive.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants explore methods to identify an irrational number between the two fractions, including examining the difference between the fractions and considering the use of a strictly increasing curve to find corresponding values.

Discussion Status

Some participants have suggested potential methods for finding an irrational number, while others have raised questions about the validity and effectiveness of these approaches. There is an ongoing exploration of different interpretations and techniques without a clear consensus.

Contextual Notes

Participants are working within the constraints of using integers for a, b, c, and d, and are focused on the properties of rational and irrational numbers in this context.

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ok,

a/b c/d

a,b,c,d are all integers
b and d are > 0

find a number inbetween a/b and b/d using a,b,c,d that is an irrational number.

thanks :!)
 
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The difference between the two rational numbers is

[tex]\frac{ad-bc}{bd}[/tex]

If you can find an irrational number that is smaller than this, you can add it to the lesser of {a/d, b/c}.

Carl
 
You could pick a strictly increasing curve (like y=x^2, for x>0), find the x values that generate these two fractions as y values, and find the y value for the number halfway (or anywhere) between these two x values. It's a safe bet this will be an irrational number.
 
CarlB said:
The difference between the two rational numbers is

[tex]\frac{ad-bc}{bd}[/tex]

If you can find an irrational number that is smaller than this, you can add it to the lesser of {a/d, b/c}.

Carl
so that will work for sure carl?
 

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