Definition:Golden Mean

Euclid's Definition


That is:
 * $A + B : A = A : B$

Also known as
The golden mean is also known as the golden ratio or golden section.

called it the extreme and mean ratio.

The Renaissance artists called it the Divine Proportion.

The notation for the golden mean is not universally standardised.

In much professional literature, $\tau$ (tau) is used, for the Greek tome for cut.

$\phi$ tends to appear more in amateur publications.

However, the notation $\phi$ seems to be becoming more widely used.

Also see

 * Equivalence of Definitions of Golden Mean


 * Continued Fraction Expansion of Golden Mean


 * Limit of Ratio of Consecutive Fibonacci Numbers where the convergents to $\phi$ are shown to be the ratios of consecutive Fibonacci numbers.