f(x) = exp(x)
xtendvers = -0.5 (slider from -10 to -0.5, step -0.1)
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] + ")")
A2 = -0.5
B2 = 0.6065306597126334
A3 = -0.5
B3 = 0.6065306597126334