t = 1.7 (slider from -5 to 5, step 0.1)
A: (t, t^(2.0))
f(x) = x^(2.0)
h = 1 (slider from 0.01 to 1, step 0.01)
B: (t + h, f(t + h))
C: (t + h, f(t))
a = Segment(A, C)
b = Segment(B, C)
c: (f(t + h) - f(t)) / h
D: (t, c)
g(x) = f'(x)