We introduce open sets in the context of the real numbers, along with examples and nonexamples of open sets. This is an important topic in the topology of the reals. We say a subset U of the reals is open if, for any x in U, there exists a deltaneighborhood of x that is contained in U. We'll prove that the real numbers are open, the empty set is open, and more! #realanalysis

Proof for Unions and Intersections of Open Sets:    • Proof for Unions and Intersections of...  

Real Analysis playlist:    • Real Analysis  
Real Analysis exercises:    • Real Analysis Exercises  

◉Textbooks I Like◉
Graph Theory: https://amzn.to/3JHQtZj
Real Analysis: https://amzn.to/3CMdgjI
Proofs and Set Theory: https://amzn.to/367VBXP (available for free online)
Statistics: https://amzn.to/3tsaEER
Abstract Algebra: https://amzn.to/3IjoZaO
Discrete Math: https://amzn.to/3qfhoUn
Number Theory: https://amzn.to/3JqpOQd

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