Gradient of a secant
Activity 1
The blue line represents the secant between 2 points.
The red line is the tangent at the point on the curve.
The horizontal distance between the two points is given by .
Use the slider to change the value of . Decreasing the value of will bring the two points closer together.
What do you notice as you reduce the distance between the 2 points?
Activity 2
What is the gradient of the secant joining and ?
Move the slider to make the distance become smaller.
What do you notice about the formula of the gradient of the secant?
What do you notice about the gradient of the secant?