9. Use an appropriate local linear approximation to estimate the value of √10. Recall that f'(a) [f(a+h)-f(a)] + h when h is very small. 10. A boat is pulled into a dock by means of a rope attached to a pulley on the dock. The rope is attached to the front of the boat, which is 7 feet below the level of the pulley. If the boat is approaching the dock at a rate of 18 ft/min, at what rate is the rope being pulled in when the boat is125 ft from the dock.