HP Prime Graphing Wireless Calculator - Manual (Page 59)

Geometry 55
In general, the inversion of point A through center C, with
scale factor k, maps A onto A’, such that A’ is on line CA and
CA*CA’=k, where CA and CA’ denote the lengths of the
corresponding segments. If k=1, then the lengths CA and CA’
are reciprocals.
Reciprocation
Given a circle and a vector of objects that are either points or
lines, returns a vector where each point is replaced with its
polar line and each line is replaced with its pole, with respect
to the circle.
reciprocation(Circle, [Obj1, Obj2,...Objn])
Example:
reciprocation(circle(0,1),[line(1+i,2),poin
t(1+i*2)]) returns [point(1/2, 1/2) line(y=-x/
2+1/2)]
Numeric view: Cmds menu
Cartesian
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.
Ordinate
Returns the y coordinate of a point or the y length of a vector.
ordinate(point) or ordinate(vector)
Example:
Example: ordinate(GA) returns the y-coordinate of the
point A.