Optimization unit

Choose TWO of the following problems to complete. 6 marks each. A. Car A is 80 km east of Car B and begins moving west at 40 km/h. At the same moment, Car B begins to move north at 70 km/h. What is the closest distance, in kilometers, the cars will be from each other M at what time t, in hours, will that distance occur? B. A landscape professional wants to make a lidless rectangular ower box whose length is four times its width. If the surface area of the box is to be 5200cm2, find the dimensions that will maximize the volume of the box. C. Arectangular storage shed, 250 cm high and 100 cm deep, is built against a wall. Calculate the shortest ladder that can reach from the ground, over the shed, to the wall' behind it