4. (12) A certain train accelerates and decelerates at the rate of 5890 mi/hrg. Its maximum cruising speed is 180 mi/hr. What is the maximum distance the train can travel if it accelerates from rest until it reaches cruising speed and then runs at that speed for 1 hour. You may use a calculator for this problem. 3 Give answer to 4 decimal places. 3. (l2) Prove: If f is continuous on [a,b] and differentiable on (61,13) and f'($)