# Tangent Line as Limiting Position of Secant Lines

This applet shows that tangent line at a point P is obtained as limiting position of secant lines through the point P. Use slider a to select point of contact P. Use button on bottom left of the geometric view to start and pause the animation.

Discuss why value of derivative at a point equals slope of tangent line.
For more on interpretation of derivative check my online book
"Flipped Classroom Calculus of Single Variable"
https://versal.com/learn/vh45au/

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