[b]"The golden number is omnipresent in math"[br]Disclaimer:[br]This isn't true, [/b][math]\varphi[/math][b] or [/b][math]\Phi[/math][b] as golden getal isn't include in any serious mathematical compendium.[/b][br]Everyone who studies math, physics or ingeneering, meets the whole Greek alphabet, however the golden number is totally absent.[br]As well in GeoGebra [math]\pi[/math], [math]e[/math] and [math]i[/math] are included and recognised in GeoGebra, but quite right nobody comes on the idea to include the number [math]\varphi=\frac{\sqrt{5}-1}{2}[/math] as an important constant.

The number [math]\varphi[/math] just appears in some niche issues.[br][list][*]For obvious reasons [math]\varphi[/math] appears in geometry when polygons and decagons appear. More about this you can find in [url=https://www.geogebra.org/m/cz8ggxgt#chapter/1133143]phi and geometry[/url].[/*][*]The number [math]\varphi[/math] also appears in applications in which the sequence of Fibonacci is involved. [br]More about how and where you can read in [url=https://www.geogebra.org/m/cz8ggxgt#chapter/1133144]phi and the sequence of Fibonacci[/url].[/*][/list]