18.100A Real Analysis (Fall 2020, MIT OCW): Lecture 05 - The Archimedean Property, Density of the Rotations, and Absolute Value

18.100A Real Analysis

18.100A Real Analysis (Fall 2020, MIT OCW). Instructor: Dr. Casey Rodriguez. This course covers the fundamentals of mathematical analysis: convergence of sequences and series, continuity, differentiability, Riemann integral, sequences and series of functions, uniformity, and the interchange of limit operations. It shows the utility of abstract concepts through a study of real numbers, and teaches an understanding and construction of proofs. (from ocw.mit.edu)

Lecture 05 - The Archimedean Property, Density of the Rotations, and Absolute Value

Instructor: Dr. Casey Rodriguez. We show that the real numbers satisfy the Archimedean property, a property we will constantly use, and we prove rationals are dense in the reals. We also rigorously define absolute values and the properties that follow from this definition.

Go to the Course Home or watch other lectures:

Lecture 01 - Sets, Set Operations and Mathematical Induction

Lecture 02 - Cantor's Theory of Cardinality (Size)

Lecture 03 - Cantor's Remarkable Theorem and the Rationals' Lack of the Least Upper Bound Property

Lecture 04 - The Characterization of the Real Numbers

Lecture 05 - The Archimedean Property, Density of the Rotations, and Absolute Value

Lecture 06 - The Uncountability of the Real Numbers

Lecture 07 - Convergent Sequences of Real Numbers

Lecture 08 - The Squeeze Theorem and Operations Involving Convergent Sequences

Lecture 09 - Limsup, Liminf, and the Bolzano-Weierstrass Theorem

Lecture 10 - The Completeness of the Real Numbers and Basic Properties of Infinite Series

Lecture 11 - Absolute Convergence and the Comparison Test for Series