The function is  and the interval is .

Apply derivative with respect to x .

Apply the difference rule of derivatives.

Apply the power rule: .

To find the critical numbers of , equate to zero.

is in the region .

Critical points in the given region is .

To find the absolute extreme of function in given region , sketch the function .

Critical point is minimum point over the interval .

Right end point is maximum point over the interval .

Minimum point is  .

Maximum point is .