human
Estimate the gradient at a point on a non-linear section of a real life graph The graph shows information about the velocity, \( v \mathrm{~m} / \mathrm{s} \), of a parachutist \( t \) seconds after leaving a plane.

Which of the following is the best estimate for the gradient of the curve when \[t=8\]? ![A graph showing time in seconds on the x axis and velocity in metres per second on the y axis. A curve is shown with a tangent to the curve drawn in at (8,51). The tangent also passes through the point (0,40)]() \( 0.72... \)
gpt
Believes gradient = change in x/change in y