http://demonstrations.wolfram.com/Osc...
The Wolfram Demonstrations Project contains thousands of free interactive visualizations, with new entries added daily.
For a given point on a function, a circle with tangency and matching curvature is known as either the circle of best fit or the osculating circle. Slide the marker along the x-axis to move the tangency point on the curve. Choose among polynomial, trigon...
Contributed by: Abby Brown