Slope of Secant and Tangent Lines
Author: John Maharry
Date: 12/16/2008

Change the value of 'h' on the slider to move the secant line.
Compare the slope of the secant line to that of the tangent line. 
What happens when h=0?

Then move the Point A to find the slope of the Tangent line at other points on the curve.

Finally, you are also able to change the function. Right Click on the curve to do so.

Change the Value of 'h' in the Slider to move the secant line. 
Compare the Slope of the Secant with the Tangent

Then move the point A and start over. 
The Green Line records the values for the Slopes of the Tangent Lines.

A = Point(xAxis)
h = 1 (slider from -1 to 1, step 0.01)
f(x) = x^(3)
B: (x(A), f(x(A)))
C: (x(A) + h, f(x(A) + h))
D: (x(A) + h, 0)
a = Line(B, C)
m: (y(C) - y(B)) / (x(C) - x(B))
g(x) = f'(x)
text1: "m \approx m_{sec} = \frac{  f(A)-f(A+h) }{ h} =" + m
text2: "m = f'(A) = " + (g(x(A)))
E: (x(A), g(x(A)))