Introduction to Differentiation - Tangents to Curves 2

Drag point A around the curve to see how the tangent changes. To enable trace, right click point B and select trace.
What is the equation of the curve? What is the relationship between point A and point B? What is the relationship between the gradient of the curve at point A and point B? After you have turned trace on, drag point A around the curve again. What do you notice? What is the equation of the new curve? Can you spot a relationship between the new curve and the original?