A proof of an area as a set function

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SUMMARY

This discussion focuses on proving that a set consisting of a single point is measurable and has zero area using Apostle Calculus. The user initially attempted to apply the Axiom of Choice and the area formula for rectangles, concluding that the area of a point is zero. However, they recognized that a point cannot be considered a rectangle, prompting a reevaluation of their approach. The user later proposed a new method involving the concept of enclosing a point within increasingly smaller rectangles to demonstrate that the area approaches zero.

PREREQUISITES
  • Apostle Calculus fundamentals
  • Understanding of the Axiom of Choice
  • Concept of measurable sets in mathematics
  • Basic knowledge of limits and area calculations
NEXT STEPS
  • Research the properties of measurable sets in measure theory
  • Study the implications of the Axiom of Choice in set theory
  • Explore the concept of limits and their application in calculus
  • Examine proofs related to area calculations of geometric shapes
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Students majoring in Physics or Mathematics, particularly those studying calculus and measure theory, as well as educators seeking to understand the nuances of proving properties of sets in mathematical analysis.

Shing
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Hi guys, recently, I am a freshmen majoring in Physics, recently using Apostle Calculus to self-study. However, I am having a hard time knowing whether if my proof is correct or not, since there isn't any solution.

Homework Statement


Prove that following set is measurable and has zero area: a set consisting of a single point.

The Attempt at a Solution



First, I have considered the Axiom of Choice of scale{Every rectangle R is in Measurable Set. If the edges of R have lengths h and k then a(R)=hk} to show that h and k both is zero therefore, a(Point)=0

but I couldn't convince myself that a point is an rectangle! So my former approach is not proper.

and I couldn't think up any other approaches so far.

would anyone be king enough to give me a few suggestions?

many thanks!
 
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Think about making really small rectangles around the point
 
Office_Shredder said:
Think about making really small rectangles around the point

Thank you very much indeed!

so here is my new approach, what would the problem be in my proof? :
let there be a point in a rectangle [itex]a^2[/itex]
[tex]\exists a\in R[/tex]
s.t. for all [itex]x\in R, 0<a<x[/itex]
[tex]\implies a^2=0[/tex]
[tex]\implies f(point)=0[/tex]
 

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