This road sign was found on northbound Loop 101 in Tempe, Arizona.

Note: The following expression approximates Phi (

`1.61803399+`

)...1 + sqrt(5) ----------- 2The road sign says...

+--------------------------------------+ | Broadway Rd/Apache Blvd 1/4 | | University Dr/Rio Salado Pkwy 1 1/4 | +--------------------------------------+ the numbers are: (1/4) (1 1/4) the math is: sqrt(1/4) + sqrt(1 1/4) = Phi observe... sqrt(1/4) = sqrt(1)/sqrt(4) = 1/2 sqrt(1 1/4) = sqrt(5/4) = sqrt(5)/sqrt(4) = sqrt(5)/2 1 sqrt(5) 1 + sqrt(5) --- + ------- = ----------- 2 2 2The key to finding Phi in this road sign was using the mixed number

`1 1/4`

as the fraction`5/4`

. The square root of`5/4`

is square root`5`

divided-by square root`4`

, which is`2`

. Thus, we get a fraction having square root`5`

in the numerator and`2`

in the denominator. The square root of the fraction`1/4`

is`1`

divided-by the square root of`4`

, which gives`1/2`

. We now have two fractions having the common denominator of`2`

and we add them together to get`1`

plus square root`5`

in the numerator.Wikipedia.org:: Golden ratio

**Creator:** Gerald D. Thurman
[gthurman@gmail.com]

**Created:** 19 April 2007

This work is licensed under a Creative Commons License.