9. As a sled is pulled over the top of snow, the frictional force on the sled varies due to the changing consistency of the snow. The graph to the right shows the function F = g(d), where F is the frictional force on the sled, in Newtons, and d is the distance that the sled has been pulled, in meters, from its starting point. (a) By drawing in an appropriate tangent line, estimate the value of g'(40), and include the proper untis. (b) Give a complete sentence interpretation of g'(40) in the con- text of this problem. F 160- 150. 140 130- 10 20 30 40 d 50

a) A curve ha's equation y = x² cos x, x € R. E Evaluate the gradient of the curve at x = π. Give the answer in terms of . dy dx

5. a) Identify f, f', and f' from the graph below. b) Sketch the graph of the derivative in the blank box. -4 c) State where the function is not differentiable and explain why.