At the nature center where I work, they've been getting ready for their Christmas auction. As a volunteer, it was one of my jobs, to make those cheep lanterns from old soup cans with holes punched in them. Putting crosses and snowflakes can only take you so far, and I did dozens of these lanterns. So, I figured I'd go nerdy and make these three in order. They are sine, cosine, and tangent waves.
In the background you can see the nature center's two bald eagles.