Texas Instruments: At a Snail's Pace for the Ti 73 Explorer

It is hard to imagine a way to mathematically describe a spiral. Spirals are commonly seen in nature. There are a number of different types of spirals. Some interesting examples include the spiral arrangements of scales in pine cones, seeds in a sunflower, or the calcified layers of a snail's shell. One way of constructing a spiral is to use the Fibonacci sequence.