January 1 - The Beatles start a 5 day tour in Scotland to support the release of their new single, "Love Me Do".
January 7 - Gary U.S. Bonds[?] files a $100,000 lawsuit against Chubby Checker, claiming that Checker stole "Quarter to Three" and turned it into "Dancin' Party." The lawsuit is later settled out of court.
... of significance for details.
Derivation
The quadratic formula is derived by the method of completing the square[?].
<math>ax^2+bx+c=0</math>
Dividing ...