latitudes of a serie of points out of the spherical coordinates
Hi, in https://www.geogebra.org/m/... I want to extract the latitudes of the 30 points of a list.
With the command arg(C) I can define the longitude (2nd coordinate of the spherical coordinates) as a separate number to use in transformations as Mercator. I don't know a similar command for the latitude (3rd coordinate). Indeed I can use asind (z(C) / R) with R the radius of the globe because in this command I can define the number range grom -inf to inf. But when I use this command in a sequence command: latitudes = Sequence(asind(z(Element(list, nn) / 5)), nn, 1, 30) the result is a list with numbers (that's OK) in which I can only define the range starting from 0° to get only positive latitudes. (Il add a file ).
A workaround I did was to define all the angles between (x(C), y(C), 0)), the origin O and C in a list and then conditionally change the sign for those angles corresponding that had a negative z-value...
So two alternatuves would make it much easier: a direct command for the 3rd spherical coordinate or the possibility to define the angles in a list also from -inf to inf as it is for a separate angle.
In the file added: if C is dragged beneath the xOy plane its latitude will become negative, but the values in the list won't.