posted by Frank .
Please help with this. I submitted it below but no one responded. I need the first derivative of f(x)=4(x+ then the square root to include (x(8-x)), then close bracket.And then the second derivative of this to show by the second derivative test that it is a local maximum. This is difficult to put into form here and I hope I have got it right. Many thanks.
It is difficult to understand your Eq
because of the way it is written.You can use sqrt for square root.