Direct Link To GeoGebra Applet

Above is a simple GeoGebra applet which shows the tangent line in red vs secant line drawn on the interval (a,a+Δx) in green. I have also included the linear extrapolated point (a+Δx, f(a)+f'(a) Δx). Use the slider to demonstrate what happens when the limit as Δx approaches 0

This work by Jason R Englert is licensed under CC BY-NC 4.0