A boat on the ocean is 4 mi from the nearest point on a straight shoreline: that point is 6 mi from a restaurant on the shore. Abby plans to row the boat straight to a point on the shore and then walk along the shore to the restaurant.
a. If Abby walks at 3 mi/hr and rows at 2 mi/h, at which point on the shore should she land to minimize the total travel time?
b. If Abby walks at 3 mi/hr, what is minimum seed at which she must row so that the quickest way to the restaurent is to row directly (with no walking).