HP Prime Graphing Calculator - Manual (Page 195)

Geometry 191
polar
Returns the polar line of the given point as pole with respect
to the given circle.
polar(circle, point)
Example:
polar(circle(x^2+y^2=1),point(1/3,0)) returns
x=3
polar_coordinates
Returns a vector containing the polar coordinates of a point
or a complex number.
polar_coordinates(point)
or
polar_coordinates(complex)
Example:
polar_coordinates(√2, √2) returns [2, π/4])
pole
Returns the pole of the given line with respect to the given
circle.
pole(circle, line)
Example:
pole(circle(x^2+y^2=1), line(x=3)) returns
point(1/3, 0)
powerpc
Given a circle and a point, returns the difference between the
square of the distance from the point to the circle’’s center and
the square of the circle’s radius.
powerpc(circle, point)
Example
powerpc(circle(point(0,0), point(1,1)-
point(0,0)), point(3,1)) returns 8
radical_axis
Returns the line whose points all have the same powerpc
values for the two given circles.
radical_axis(circle1, circle2)