HP Prime Graphing Wireless Calculator - Manual (Page 47)

Geometry 43
Line
Draws a line. The arguments can be two points, a linear
expression of the form a*x+b*y+c, or a point and a slope as
shown in the examples.
line(point1, point2)
or
line(a*x+b*y+c)
or
line(point1, slope=realm)
Examples:
line(2+i, 3+2i) draws the line whose equation is
y=x–1; that is, the line through the points (2,1) and (3,2).
line(2x–3y–8) draws the line whose equation is
2x–3y=8
line(3–2i,slope=1/2) draws the line whose equation
is x–2y=7; that is, the line through (3, –2) with slope m=1/2.
Parallel
Draws a line through a given point that is parallel to a given
line.
parallel(point,line)
Examples:
parallel(A, B) draws the line through point A that is
parallel to line B.
parallel(3–2i, x+y–5) draws the line through the point
(3, –2) that is parallel to the line whose equation is x+y=5;
that is, the line whose equation is y=–x+1.
Perpendicular
Draws a line through a given point that is perpendicular to a
given line. The line may be defined by its name, two points,
or an expression in x and y.
perpendicular(point, line) or
perpendicular(point1, point2, point3)
Examples:
perpendicular(GA, GD) draws a line perpendicular to
line D through point A.
perpendicular(3+2i, GB, GC) draws a line through
the point whose coordinates are (3, 2) that is perpendicular
to line BC.