Notes on the Complex Roots of Unity(eli.thegreenplace.net)
28 points by sks_15 | 5 comments
A blog post by Eli Bendersky explaining the roots of unity, starting from real-number roots and building up to complex roots.
#algebra on Hacker News
2 stories tagged algebra, newest first.
A visual proof that a^2 – b^2 = (a + b)(a – b)(futilitycloset.com)
634 points by beardyw | 174 comments
A Futility Closet blog post showing a diagrammatic visual proof that a² − b² = (a + b)(a − b), with a Sophie Germain quote.