For each problem, find the x-coordinates of all points of inflection, find all discontinuities, and find the open intervals where the function is concave up and concave down. 7) 1- -72-6r-4 8 ) 5 - (58 - 15) 9) 1(1) - - 41 +5 For each problem, find all points of relative minima and maxima, 10) 8- (25 + 8)2 11) y - - 2 12) 1 - - 2r + 2 Solve each optimization problem. 13) A supermarket employee wants to construct an open-top box from a 10 by 16 in piece of cardboard. To do this, the employce plans to cut out squares of equal size from the four corners so the four sides can be bent upwards. What size should the squares be in order to create a box with the largest possible volume