Find the maximum and minimum values of the function f (x) = 1 / 3 x to the third power - 21x square + 1 in the interval [- 1,4]

Find the maximum and minimum values of the function f (x) = 1 / 3 x to the third power - 21x square + 1 in the interval [- 1,4]

In this paper, we want to find out the results of this paper, we are as follows: 1 / 3 * 3x 35\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\it's not easy