O = Intersect(xAxis, yAxis)
d = Rotate(c, 315.0*°, O)
Roteren = 0 (slider from 0 to 1, step 1)
A = Point(If[Roteren > 0.0, d, c])
C: (y(A), x(A))
B: (x(A), -y(A))
Opgave = 1 (slider from 1 to 2, step 1)