A = (50, 28)
B = (90, 70)
C = (130, 129)
a = 0 (slider from 0 to 0.1, step 1.0E-4)
b = -5 (slider from -5 to 5, step 0.001)
c = -5 (slider from -5 to 5, step 0.001)
f(x) = (a * x^(2)) + (b * x) + c
D = Point(f)