The graph of a function f is shown 800 400 0 0 20 40 c Compute the following f 40 f 0 40 0 60 a Find the average rate of change of f on the interval 50 60 b Identify an interval on which the average rate of change of f is 0 O 20 40 O 0 80 O 0 60 O 10 40 O 10 50 X What does this value represent geometrically O the slope of the tangent line at 0 f 0 d Estimate the value of f 50 O the slope of the tangent line at 40 f 40 O the slope of the line segment from 0 f 0 to 40 f 40 O the slope of the tangent line at 20 f 20