If a box with a square cross section is to be sent by a delivery service there are restrictions on its size such that its volume is given by V x 54 2x where x is the length of each side of the cross section in inches a Is Va function of x Yes V is a function of x No V is not a function of x b If V V x find V 15 and V 19 If V is not a function of x enter DNE V 15 V 19 c What restrictions must be placed on x the domain so that the problem makes physical sense Enter your answer using interval notation If V is not a function of x enter DNE