Outside of the united states, the common paper size is called A4 and measures 21 by 29.7 centimeters. Let V(x) = (21-2x)(29.7-2x)(x) be the volume in cubic centimeters of a box made from A4 paper by cutting out squares of side length x in centimeters from each cornor and then folding up the sides. What is a reasonable domain for V in this context? Explain or show your reasoning