Rational exponents in the real number system?

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SUMMARY

The discussion centers on the need for rigorous texts that address raising real numbers to rational powers without resorting to complex analysis. Participants express a desire for authoritative resources that provide clear definitions and answers to specific questions, such as the evaluation of expressions like ##(-8)^{4/6}## and ##(1)^{5/0}##. The conversation highlights the lack of comprehensive literature on this topic, particularly in works like "Principles of Mathematical Analysis" by Walter Rudin, which does not adequately cover the exponentiation of negative numbers in a rigorous manner.

PREREQUISITES
  • Understanding of rational exponents and their properties
  • Familiarity with real analysis concepts
  • Basic knowledge of mathematical rigor and definitions
  • Awareness of complex numbers and their implications in exponentiation
NEXT STEPS
  • Research authoritative texts on real analysis that cover exponentiation of negative numbers
  • Explore mathematical literature that discusses rigor in definitions and notation
  • Investigate alternative resources that address rational exponents without complex analysis
  • Examine discussions on mathematical rigor and its varying interpretations in academic contexts
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Mathematics students, educators, and researchers seeking a deeper understanding of rational exponents in the real number system without the influence of complex analysis.

Stephen Tashi
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Are there rigorous texts that treat the topic of raising real numbers to rational powers without treating it a special case of using complex numbers?

I'm not trying to avoid the complex numbers for my own personal use! My goal is to determine whether students who have not studied complex analysis can find authoritative answers.

In casual discussions, people are quick to offer answers to questions such as:
1) Is ##(-8)^{4/6} ## equal to ##(-8)^{2/3}##?
2) Is ##(1)^{5/0}## defined as the 5th power of the zeroth root of 1?

but what texts give authoritative answers to such questions and develop definitions for the above notations in a manner that is self-consistent?

Usually when the topic of raising a negative number to a rational power comes up, the answers refer to complex numbers. Has any author taken up the thankless task of treating this topic in a rigorous fashion without using complex analysis?
 
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Stephen Tashi said:
in a rigorous fashion without using complex analysis?

"Rigor" means different things to different people. What do you think is legit and what do you not? In short - can you describe what an answer would look like?
 
Vanadium 50 said:
"Rigor" means different things to different people. What do you think is legit and what do you not? In short - can you describe what an answer would look like?

I imagine a text on "Real analysis" that defines the exponentiation of negative numbers. As a non- example, I don't find such a definition in "baby Rudin" ( Principles of Mathematical Analysis ).
 

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