Consider the function f(x)=9+3x1.5x2,2.5x4\displaystyle {f{{\left({x}\right)}}}={9}+{3}{x}-{1.5}{x}^{{2}},\quad{2.5}\leq{x}\leq{4}.

The absolute maximum occurs at x\displaystyle {x} =  

The absolute minimum occurs at x\displaystyle {x} =  

7.125\displaystyle {7.125} and 3\displaystyle -{3}