How Do You Determine the Least Upper Bounds of N and P in Repeating Decimals?

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Discussion Overview

The discussion revolves around determining the least upper bounds of N and P in the context of repeating decimals, where x is represented as a real number in a specific decimal format. The scope includes mathematical reasoning and exploration of properties of rational numbers.

Discussion Character

  • Exploratory, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant states that the problem has no answer, suggesting that both N and P are unbounded without additional conditions.
  • Another participant argues that the repeating nature of the decimal implies that x can be expressed as a fraction A/B, allowing for bounds on N and P based on A and B.
  • A further contribution clarifies that for specific rational values of x, N and P can be determined, but asserts that no bounds exist when considering all rational numbers.

Areas of Agreement / Disagreement

Participants express disagreement regarding the existence of bounds for N and P, with some asserting that bounds can be established under certain conditions while others maintain that they are unbounded in general.

Contextual Notes

The discussion highlights the dependence on the definitions of N and P, as well as the conditions under which the bounds may or may not apply. There is an unresolved aspect regarding the generalization of the problem to all rational numbers.

Ed Quanta
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I have to find the least upperbounds on N and P where x is an element of the reals and represented by the repeating decimal

x=m.d1d2...dNdN+1...dN+P instead of underlining I meant for this to be an overline representing the repeating sequence of digits in the decimal
 
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The problem as stated has no answer. Both N and P are unbounded, unless there are other conditions which you haven't presented.
 
I beg to differ with mathman.

the fact that the decimal is repeating implies that the real number x is a fraction A/B where A and B are integers. then it makes sense to give a bound on N as well as on P in terms of A and B.

I.e. N is the number of terms until the decimal starts to repeat and P is the length of a cycle after it starts repeating in cycles of the same length. It seems to me that if you just look at what happens when you divide A by B, you will see how to do this.
 
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For any specific rational x, you have specific values for N and P. However, there are no bounds when considering all rationals.
 

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