Secant Line
This illustrates the slope of a secant line on a curve. The play button advances the construction.
Step 1 - Shows the graph of the function , and a point A on the curve. The point may be moved along the curve.
Step 2 - A point B is added to the right of point A. The x distance between the points can be controlled with the slider. Left and right arrow keys can fine set the slider.
Step 3 - Draws a purple dashed secant line through the two points.
Step 4 - Calculates the slope of the line through the two points.
Step 5 - Shows a pink tangent line and the slope of the tangent line.