\fThe following graph illustrates distance vs time of a moving object. Use the graph to answer the following questions. [4 marks] Position Time a) In what interval(s) is the object moving towards the origin? b) In what interval(s) is the objects' velocity positive? c) When does the object change direction? d) Describe the motion on the interval EF. 3. The line 8x y 8 = O is tangent to the graph of f(x) = (x + k)(x2 1) at the point (1, 0). Find the value of k. 4. A company sells an average of 50 skateboards pe month at a price of $120 each. For each $5 decrease in price, two more skateboards are sold. Determine the marginal revenue when 25 skateboards are sold