Month: September 2017

Euler’s formula in a children’s book

Originally posted on David Richeson: Division by Zero:
As you may know, I wrote a book on Euler’s polyhedron formula. (Euler’s formula says that every polyhedron with V vertices, E edges, and F faces satisfies V-E+F=2.) I gave a talk recently during which I lamented that kids aren’t taught this beautiful theorem; after all, it…

Read More Euler’s formula in a children’s book

The Division Symbol Goes Viral

Originally posted on David Richeson: Division by Zero:
A few days ago a Twitter user with the handle @Advil posted the following tweet: https://twitter.com/Advil/status/907092348345241601 As you can see, the tweet was widely “liked” and retweeted. I was wondering: Is it true? I don’t know much about the history of the division symbol ÷, although I…

Read More The Division Symbol Goes Viral

Álgebra Moderna 1. El radical de Jacobson en un anillo artiniano es nilpotente.

Aquí esta la demostración directa y sin cocientes: https://books.google.com.mx/books?id=lBO7BAAAQBAJ&pg=PA265&lpg=PA265&dq=artinian+jacobson+is+a+nilideal&source=bl&ots=2LApNZXJbv&sig=djGmFvRkW_r0srIr9LofQsH1lnU&hl=es&sa=X&ved=0ahUKEwi4h7Wi8pDWAhUH4mMKHX3xBnMQ6AEIODAC#v=onepage&q=artinian%20jacobson%20is%20a%20nilideal&f=false

Read More Álgebra Moderna 1. El radical de Jacobson en un anillo artiniano es nilpotente.