Reading a bit about the history of algebra in The Joy of x: A Guided Tour of Math, from One to Infinity, I was inspired to prove the quadratic formula I was originally taught in high school (and had reiterated this past semester in two courses at Indiana University East). The Arabic Santa is a shout out to Mohammad bin Musa al-Khwarismi, who we owe a lot to when it comes to algebra and working with quadratic equations. However, this article is a good reminder that we ultimately owe lots of folks and cultures credit for the quadratic formula.
Without further ado, my proof. Merry Christmas! [Read more…]