Plot the curve f (x) = 4x2 −1 for values of x from x =−1 to x =+4. Label the coordinates (3, f (3)) and (1, f (1)) as J and K, respectively. Join points J and K to form the chord JK. Determine the gradient of chord JK. By moving J nearer and nearer to K determine the gradient of the tangent of the curve at K.