rectangular_coordinates and polar_coordiantes

[Eddie W. Shore]

It turns out that the HP Prime does have rectangular-polar conversion functions. They are buried in the catalog.

Syntax:

rectangular_coordinates(r, θ) or rectangular_coordinates([r, θ]) returns the vector [x, y]

Example: (Radians mode - CAS mode, works in Home mode too)
rectangular_coordinates(3, π/3) returns [3/2, 3*√(3)/2] (≈ [1.5, 2.59807621135] )

polar_coordinates(x,y) or polar_coordinates([x,y]) returns the vector [r, θ]

Example:
polar_coordinates(3,4) returns [5, ATAN(4/3)] (≈ [5, .927295218002] )