Concept of derivative
(a bentech Presentation)

Derivative-Graph

f(x) = x^(3) / 18 - x^(2) / 4 + 4
a = 5.47 (slider from -5 to 8, step 0.01)
A: (a, f(a))
b = Tangent(A, f)
m = Slope(b)
D: (a, 0)
E: (a, m)
c = Segment(E, D)
B = Midpoint(E, D)
text1: "m=" + (LaTeX[m]) + ""
text2: "f(x)=" + (LaTeX[f]) + ""
g(x) = x^(2) / 6 - x / 2
text3: "f'(x) = " + (LaTeX[g]) + ""