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 06 - The Uncountability of the Real Numbers
Instructor: Dr. Casey Rodriguez. We prove the humble, but powerful, triangle inequality, and show that the real numbers are uncountable, and thus the irrational numbers greatly outnumber the rational numbers. We introduce sequences and limits of real numbers.