From a 36-inch by 36-inch piece of metal, squares are cut out of the four corners so that the sides...

From a 36-inch by 36-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 quares, in inches, that are cut out. Express the volume of the boz as a function of x. Give the function and state its domain.