Inverse trigonometric functions, or cyclometric functions:
arcus sinus - arcsin(x)
arcus cosinus - arccos(x)
acrus tangent - arctan(x)
arcus tangent 2 - arctan2(x,y)
They would be really helpful, when going from the cartesian coordinate system into a polar coordinate system.
Looking at what is need to provide ‘Islamic Calendar’ … which is based on declination of Sun.
This will need: asin(x), acos(x), and atan2(x, y)
Discussed here:
“Facer has an atan function that works in the designer, however it does not work on the actual watch (neither do asin or acos). … You can however, approximate atan, with some error …”