Happy Valentine's Day!

For a fun surprise, type this expression into a Google search:

sqrt(cos(x))*cos(300x)+sqrt(abs(x))-0.7)*(4-x*x)^0.01, sqrt(6-x^2), -sqrt(6-x^2) from -4.5 to 4.5

(or just click here) and have a mathematically accurate Valentine's Day!

History of Valentine's Day

Merry Christmas!

Here's a short video from the History Channel about how Christmas originally became a holiday.