Tangent Line Versus Secant Line

Instructions:
  • Use the drop down menu to select a function.
  • The blue line is a secant to the function through points A and B.
  • The green line is a tangent to the function through point A.
  • Drag points A and B to see how the slopes of the tangent and secant lines change.
  • Drag point B closer to point A and see what happens to the slopes of the secant and tangent lines as B approaches A.