6-7) Work-out a Calculus-based analysis of properties then sketch the graph of f(x) = 2x2 - 7x - 15 8-9) A rectangular box is to be made from a piece of cardboard 12 in long and 5 in wide by cutting out identical squares from the four corners and turning up the sides. Find the volume of the largest rectangular box that can be formed. 10) A ladder 7 meters long is leaning against a wall. If the bottom of the ladder is being pushed horizontally towards the wall at 3 m/s, how fast is the top of the ladder moving when the bottom is 5 meters from the wall