f(x) = x^(2)
xtendvers = 0 (slider from -100 to 0, step -2)
M: (xtendvers, f(xtendvers))
P: (xtendvers, 0)
N: (0, f(xtendvers))
mn = Segment(M, N)
mp = Segment(M, P)
A1: "x(" + (Name[M] + ")")
B1: "y(" + (Name[M] + ")")