We need to obtain the first derivate
[tex]\begin{gathered} f\mleft(x\mright)=-\frac{1}{2}x^2+4x-11 \\ f^{\prime}(x)=-x+4 \end{gathered}[/tex][tex]\begin{gathered} f\mleft(x\mright)=-2x^2+16x-35 \\ f^{\prime}(x)=-4x+16 \end{gathered}[/tex][tex]\begin{gathered} \: f\mleft(x\mright)=\frac{1}{2}x^2-4x+5 \\ f^{\prime}(x)=x^{}-4 \end{gathered}[/tex][tex]\begin{gathered} f(x)=2x^2-16x+5 \\ f^{\prime}(x)=4x-16 \end{gathered}[/tex]
