# Phi

## Phi

*Phi *is the 21st letter of the Greek alphabet. Among other things, the character is used to represent the Golden Ratio; a ratio of a and b where a:b = (a+b):a. The only solution to this relation is *phi*, 1.618. A rectangle of a and b is a Golden Rectangle. Geometry based on phi is supposed to be aesthetically pleasing and phi appears in various branches of mathematics, particularly the Fibonacci sequence.

The Fibonacci sequence is the sequence of natural numbers given by F(n) = 0 for n = 0; F(n) = 1 for n = 1; F(n) = F(n-2)+F(n-1) for n > 1. Or 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, … Dividing consecutive members of this sequence gives a value that approaches phi as n approaches infinity.

**Phinetune** gets the first part of its name from the word Phi. Reasons for its use comes from the ability to use it in deliberate misspelling of words, like finetune; the fact that phi is mathematically so interesting appeals; and its symbol is quite eye catching.