HP Prime Graphing Calculator - Manual (Page 186)

182 Geometry
Example:
slopeat(line(point(0,0), point(2,3)),
point(-8,8)) displays “sline(point(0,0),
point(2,3))=3/2” at point (–8, 8)
slopeatraw
Works the same as slopeat, but without the label.
Numeric view: Cmds menu
Measure
abscissa
Returns the x coordinate of a point or the x length of a vector.
abscissa(point) or abscissa(vector)
Example:
abscissa(GA) returns the x-coordinate of the point A.
affix
Returns the coordinates of a point or both the x- and y-lengths
of a vector as a complex number.
affix(point) or affix(vector)
Example:
if GA is a point at (1, –2), then affix(GA) returns 1–2i.
angle
Returns the measure of a directed angle. The first point is
taken as the vertex of the angle as the next two points in order
give the measure and sign.
angle(vertex, point2, point3)
Example:
angle(GA, GB, GC) returns the measure of ∡ BAC.