Let V = x3 -7x2+12x dV/dx = 3x2-14x+12 Setting dV/dt = 0 we find that the two values of
x = 1.131 and 3.535
Substituting these values into the Volume formula we get
V = 6.065 if x = 1.131
V = -.879 if x = 3.535 However, these values are local maximum value canidates and the equation & problem contains no constraints. So any x value greater than x = 4.67 gives a volume greater than 6.065! Therefore, there is no distinct absolute maximum for this problem!