Hi Mr Sasho,
I'd like to know how to solve exercice number (5)in:
x,x,y = dimensions of the box
S=area of the box (no lid).
It is given that S=1200 so that x2+4xy=1200 and so y=(1200-x2)/4x. Put this in the formula for the volume to get V=x2(1200-x2)/4x, and use our theory to find the absolute maximum of that function.