From a 15-inch by 15-inch piece of metal, squares are cut out of the four corners so that the sides can then be folded up to make a box. Let x represent the length of the sides of the squares, in inch
that are cut out. Express the volume of the box as a function of x. Graph the function and from th
graph determine the value of x, to the nearest tenth of an inch, that will yield the maximum
volume.