The first derivative is 3x 2-27, which makes it =0, x=3 or -3, so the maximum value x=-3 is 54 and the minimum value x=3 is -54.

The reciprocal of the second question is 3-3x 2, which is also 0, and the two roots are-1 and 1, so x=- 1 takes the minimum value as -2, and x= 1 takes the maximum value as 2.