T359

a = 1 (slider from -5 to 5)
b = 1 (slider from -5 to 5)
c = 1 (slider from -5 to 5)
f(x) = (a * x^(2)) + (b * x) + c
A = Point(f)
B = Point(f)
C: ((x(A) + x(B)) / 2, f((x(A) + x(B)) / 2))
g = Line(B, A)
h = Tangent(C, f)