k = 0.4 (slider from -5 to 15, step 0.05)
c: (k * y^(2)) - x - 1 = 0
r: y = 1
s: x = 0
A = Intersect(c, r)
B = Intersect(s, yAxis)
C, D = Intersect(c, s)
f = Segment(A, C)
g = Segment(A, D)
E = Midpoint(C, A)
F = Midpoint(A, D)
luogo1 = Locus(E, k)
luogo2 = Locus(F, k)