f(x_1)

f(x_2)

k = 1 (slider from -1 to 1, step 1)
x_1 = (1, 0)
x_2 = (3, 0)
f(x) = (k * (x + 1.76)^(2) / 12) + 0.86
A: (x(x_1), f(x(x_1)))
B: (x(x_2), f(x(x_2)))
a = Segment(x_1, A)
b = Segment(x_2, B)
C: (0, f(x(x_1)))
D: (0, f(x(x_2)))
c = Segment(A, C)
d = Segment(D, B)