Open-box Problem. An open-box (top open) is made from a rectangular material of dimensions a=8a=8 inches by b=6b=6 inches by cutting a square of side xx at each corner and turning up the sides (see the figure). Determine the value of xx that results in a box the maximum volume.

(1) Express the volume VV as a function of xx: V=V= 4x328x2+48xCorrect (2) Determine the domain of the function VV of xx (in interval form): $\left[0,3 ight]$[0,3]Correct (3) Expand the function VV for easier differentiation: V=V= 4x328x2+48xCorrect (4) Find the derivative of the function VV: V'=V= 12x256x+48Correct (5) Find the critical point(s) in the domain of VV: 3Incorrect (6) The value of VV at the left endpoint is (7) The value of VV at the right endpoint is (8) The maximum volume is V=V= (9) Answer the original question. The value of xx that maximizes the volume is: